As an Engineer I just can say THANK YOU for that good video about this topic! I saw a ton of videos about this topic (and rpm ranges in general) and most of them seem to consist of hear say and "what my old grandfather told me"-stuff. It highly depends on the car, usually diesel engines are more happy with low rpm than gasoline engines but lugging them all the time will give you higher blow by rates in general. Furthermore as you've noted, you don't save fuel just by driving in low rpms, you're saving fuel by driving in the rpm range where the engines has its top torque output. As an example you've got the 1.9 TDI (engine code 1Z) from VW. This turbo diesel engine has a max. torque of 202Nm at 1850rpm. Driving it below that makes only sense if you don't need power, if you're gliding the road. If you need power for e.g. an overtake then you want to be in the range of elasticity of the engine. It is the range between max torque and max power. In case of our example, it is between 1850rpm and 4000rpm (max power there), the redline is at ~4500rpm and the ECU drastically decreases the power at about 4250~4300rpm. I usually shift down to reach about 2200 to 2500rpm to start the rapid acceleration, it pulls good enough to shift to the next gear in the range of 3500rpm, which sends it back to about 2500rpm, and gives the opportunity for a second push. I rarely hit the redline, since the power rapidly goes down after 4100-ish rpm. Which isn't uncommon for older turbo diesel engines, since they protect themselves from excessive temperatures of the exhaust gases, which gets more dangerous if the rpms are higher due to the higher amount of gasses (mass there of). If you are a hyper miler or someone who really wants to know how to do it right in your car, get the torque diagrams. You can find them on the internet for the most cars and engines. Be sure to validate the revision (date of construction), version and engine code of the engine you have in use. Safe roads and all the best, Bruce
Thanks my friend, I really appreciate the kind words of support, I had no idea this video would be so popular especially as there are fewer drivers with a manual than ever, but it does seem that there are lots of drivers with bad habits out there. And let's face it we could all do with developing mechanical sympathy for our engine. I didn't explain a few points as well as I'd have liked in this video so I will revisit this topic in future to clarify those.
@@torquecars You're welcome :) Congratz for your video took up, it was a ton of work for sure :D Ha, yes, you couldn't stiff everything in one video, like a lecture at the University. Better split them up and give every video a critical of the topic. I'm looking forward to, until then, take care and safe roads!
I also have 1.9 tdi, love that engine. I didn't know about diagrams and max torque, but just from feeling I knew that a little bit below 2k is sweet spot for the engine. And then my father drivers 1.6 tdi on 1.2k rpm - it hurts me to watch that, to listen to those low frequency vibrations (btw, what is that low frequency sound when driving low rpm under load?). Told him many times that it's not good nor for the engine, nor for the mileage, but he just didn't listen to me. Nothing I can do about it.
@@BruceCarbonLakeriver you know, I'm not gonna try to counter what you've said, since it seems completely true and I am by far not well acquainted with engine design. But I do believe that low or high rpm don't really matter in my 55hp, 3 cylinder 1.2 Liter polo. It just always tries to force an immovable object into motion XD
I drive a 2L TDI for work and my buttdyno told me that it delivers most power at 1750-2500 rpm, full throttle above or below that range just makes the van vibrate/shake. And from what littl' I know about engineering is that vibration is the enemy of any mechanical system. Also, from a mileage point of view, if your vehicle starts shaking when throttling, that enermy isn't going into moving you forward, but side to side instead, so ease off a littl'
Well my motorcycle 125cc 4 stroke has a bit more than 40K KM and now to do a full fuel tank I need to top up almost the full engine oil in like 3 times and that's the reason of being 95% or more always in high RPM but due to the lack of power it just needs full accelerator and full rpm all the time sadly ☹ The thing is it barely even smokes unless at like RPM cut just a very tiny bit, its like the damn oil is just evaporating from inside the engine FFS, also not a single drop of oil ever dropped either, the whole engine is all dry from the outside.
@@Athaion0 7K??? mine goes a lot to 115000 rpm LOL it's the rpm cut, it doesn't have a rpm gauge but it's around there... but like 9 - 10K is more constant.
It makes sense that you should never give full throttle at low revs. The cylinders will then become much too hot, which can cause the rings to crack, as Subaru also advises. Now that rarely happens in Europe, because the petrol is of much better quality, but if you live in the USA, be careful..
I will never redline my SPI. The thing sounds like it’s ready to quit at 2,500-2,800 rpm. I’m good on taking that chance 😆maybe if I had the Zetec or Duratec
Lugging has ruined more engines than revving, rule of thumb, if you press down on the accelerator and your vehicle dose not accelerate easily then you need to down shift and if you are giving more gas to maintain your speed you need to down shift, it is just that simple. How ever revving your engine to high rpms with no load on it is not good for it either.
There's limits to it throttles are throttles not a switch there's controll to it if it's juddering and banging to much load for the rpm lift low rpm doesn't destroy engines neither does using revs it'd mostly just down to your load variable tbf most things just die from black death and lack of servicing never seen grannieing break anything even when it's come to giving a car it's first kicking after 90k miles 😂
@@tofuguru941 i think that full throttle up to redline going downhill is where there's no load, and very bad. Uphill there is engine load. Or when towing. But I'm not sure what the poster exactly meant.
@@tofuguru941your engine is meant to be loaded up. Maybe not 100% load at 1k rpm, but 90% of the time your engine is under load, so I'm going to assume they build it to be under load. But I'm not sure really. It could be the speed at which the rpms rise. Not enough time for the oil to make it to critical components.
My mother got so lazy at shifting. She would drive through town without down shifting, doing 35mph in 5th gear. She killed two or three cars like this. I finally told her to stop driving manuals, and buy automatics.
Automatics aren't necessarily the best answer. I drive an auto which is very reluctant to change down; if left to its own devices it would slog up hills all day at below 1000rpm, so I frequently find myself manually selecting a lower gear to ease the load on the engine.
@@saxon-mt5by as a co-driver on a garbage truck that's automatic,i agree. The automatic is perfect anywhere else for the type of vehicle it is, but hills are problematic as it struggles to select a proper gear.
@@Deceit-hx7ey Would lifting off or pressing down on the pedal for a moment make it downshift. Automatics are "dumb" computers that don't want to shift if you don't change the throttle input.
@@modarkthemauler there is actually a semi-mechanic mode on the truck that is engaged with a button on the wheel, there you can go higher or lower by 1 gear. So that kinda solves the hill and automatic issues lol.
Diesels in particular need to be driven like the police are chasing you..(DPF, EGR and rxhaust cleaning). My grandad told me Diesels are designed to work, not rest…Also they need a good run to build heat and regular services..to keep them fit..
Diesels are true tanks if serviced regualy, They are literally designed to haul heavy loads over long distances. Our nanny state should never had declared war on them.
Many modern cars encourage this sort of behaviour. Auto's change up too early to keep the engine at low RPM, and many manual cars with gear change indicators often make you change up too early. Like many eco features they seem to prioritise a few MPG over engine longevity.
Yes, few engines suffer from doing low rpm for extended periods with little to no load on them, (with the exception of the badly designed oil pumps out there). Keeping low RPM and pressing hard on the throttle will add wear and tear, although the degree with which this happens will vary from engine to engine.
@@torquecars There are many vehicles that have worn out prematurely because they had extended idling which is why Police package vehicles frequently have upgrades designed for extended idling. Newer vehicles have variable displacement or even electrically operated oil pumps to negate the necessity of these special packages.
@@lassepeterson2740 depends on road, your gearing, and speed limits. Your clutch probably doesn’t like starting in 2nd all the time, but not a big deal. More wear when people rest their door on clutch
I’ve been red lining my Ford fusion every day for 304,000 miles and counting. My engine seems to really like it honestly. As long as you change your oil and coolant on time I think it’s actually good for the engine
I’ve been driving for 40 years and although I’m no engineer I have pretty much driven the way you describe in this video - ie I use light throttle at low revs and while I do drive for economy on average I do indeed approach the red line from time to time and on a twisty road I will usually hold onto a lower year which is also safer as it gives more control and better response. Cars that I have owned have consequently remained healthy into high mileage and tend to burn very little engine oil.
@@Xenon777_ I would say anything below 2K is low and even around 2K I would only gradually increase the throttle rather than stamp on it. For full throttle it’s best to be close to the mid-range torque. Obviously this varies from engine to engine - I have a 1.4 TSi which is a low pressure turbo.
My opinion is that a gasoline engine car can be used between 2000 and 4000rpm with no problem if one wants some torque. Over 4000rpm, one is either looking for power, or for engine problems. Below 2000, if you are not accelerating to reach your usual speed, you are decelerating to stop the car or looking for a car park place; anything other than this is lugging the engine, and looking for mechanical problems too. In a diesel engine, I would say the torque band is between 1000 and 2500rpm. Over 3000, you are looking for power (on an engine supposedly full of torque) or, once more, looking for technical problems
@@oscaraurelio8869 my personal non professional opinion on diesel engines as i have the most experience with diesel engines is Allways ride the torque curve My car peak torque is at around 2000rpm as most diesel engines I ride it at around 2500 since its a bmw and its really revs happy, if i need to drive at under 2000rpm that means im in too low of a gear While thats the case with my revs happy engine My ford focus is not really revs happy and its made for economy in mind i change at 2000rpm and ride it around 1800 fo 2200 depending on conditions
Oscar is right for the average engine. I've always found keeping a 4 or 6 cyl avg compression gasoline motor between 2000 and 4000rpm 90% of the time to equal long engine life and best fuel usage. I have always been able to shift from 5th to 4th or 3rd in time to achieve a pass, a climb or an engine braking as I live in the mountains with steep switches. My wife can't seem to get comfortable with a clutch so she has a 6 sp electric automatic...it responds very quickly to throttle input in a pass or climb... I do not ever sense lugging or knocking. I typically keep cars since 1990 to 200k or 250k, and sell them because I have just grown tired of them after 15 to 20 years...or the subcomponents start failing with age...wiring, electric windows, switches, trim, alternators, pumps, etc... Every redliner I know was always having motor work done on a regular basis over 0 to 100k miles...or replacing the motor or engine. They may not be related...as it may just be the enthusiast race fan personality that desires constant car attention. When I drove a BMW, there were lots of trim and body parts available in junkyards because the car had blown a motor in hard kid driving or dumping it into 2nd at high speeds.
Have run a 1990s Ford for over 300k miles, nearly all of the time changed gear between 2000-2200 RPM. Engine still sounds sweet, 5k oil changes have helped
It’s ok to use lower RPM when car is still cold because cold oil doesn’t flow as quickly, but after it warms up it’s completely fine to use the whole RPM range every once in a while
All modern oils these days flows immediately, we're talking seconds. It's not exactly going from molasses to water in viscosity change. Just look at the oil flowing from a new bottle very liquid. Also specifically made to flow just fine in sub zero temps hence the W-rating. So at -20°C I can see a slight need to not overdo it the first 5 minutes but the oil is indeed flowing or any engine would be toast at every cold start
@rosen9425 that is very true, But just because the oil is flowing it still doesn’t mean it is up to operating temperature. Which is why it is a good idea to take it easy for the first few minutes before driving the car aggressively.
@@FGNi-em9sb Engine oil doesn't have to be at operating temperature to lubricate, it does that all the time. The enemy of lubrication is old oil. The older the less lubrication properties are left. It's why have to change it. All engine oils in a normal cars are multigrade oils, designed to operate at various temperature intervals. There's a cold and hot viscosity rating meaning the oil properties change as the heat increases. Excessive heat does break down the oil so abnormal heat over 100°C or so is much worse than freezing temps until extremes of -40°C or so. A funny BMW note I read in a manual said something like this. Engine break in: keep the speed below 200 kmh the first 1500 km What is driving aggressively and why is that a parameter to take into account at all? Sounds like abnormal behavior subject to a mentality attitude correction more than babying the engine oil in a car 🤔
Most modern engines are alloy with steel stretch bolts clamping the head down. They don't reach full clamping force on the head gasket until full operating temperature is reached so it is good to avoid wide open throttle operation until warmed up to avoid head gasket failures.
Thanks for the video. I am a retired motor tech. I know you say not to criticise you but after a lifetime of using the terminology of the higher the numerical number of the gear directly equates to the higher the ratio. But you say lower gear which as I said after a lifetime grates on my sensibilities. I was taught to drive ( especially on the open roads ) to keep the revs between 2 - 4 K rpm. Over 4K and you start to increase engine wear. If you are travelling around town at 30 it is better to be in 3rd gear rather than 4th for the same reasons you gave of less strain on pistons and crankshaft. Strangely fuel economy is better as well. Keep posting.
This is a bit outdated, though. Just a detail, some cars have gear selection suggestions. If you are not or barely under load, the gear selection suggestion, suggests rpm around 1200. Also, most modern (normal day to day use) engines have almost maximum torque above 1500 rpm to 4000 rpm. So it will almost never be necessary to exceed 2500 rpm unless you tow something heavy.
Cheers buddy, I try to use terms that Most of the general public will interpret correctly, but totally dropped the ball there trying to simplify. I think though I can probably get away with more technical concepts if I explain them fully.
I knew this would produce a debate. As I said in my original post I have been driving for 52 years and know what I'm talking about. The guidance I gave applies equally now as to then . It is necessary to keep strain on an engine to a minimum. Lugging has wrecked thousands of engines. I've had a car for up to 20 years and when I had to scrap it through rust the engine was still perfect.
Would it matter for cvt? Genuine question. My cvt likes to keep the rpms low when accelerating. It accelerates just fine just wondering if I need to start throttling more for more rpms or not.
It literally takes checking the instant fuel consumption to understand that lugging your engine actually uses more fuel than the correct rpm, especially going uphill.
@@nielsonderbeke8507 k9k (renault 1.5 dci) in my case. It's very obvious in hill climbs when I downshift, going from ~1500rpm to ~2300... goes from about 15-16l/100km to ~12-13. I guess it has to spray a lot more at those low rpms to keep pulling the weight up. In level driving it doesn't change much.
@@25myma but you say on hill climbs, which is like 2% of the time for the avrage person. What happens if u go on a straight road and go from 1500rpm to 2300 with a lower gear. Does your fuel consumption go down again?
@@25myma looool 15L/100km in the 1.5DCI ?? What the actual fuck are u talking about that can't be right, even if u keep driving at 3000rpm for 4 hours at 120kmh it would never get past 7L, ideally it would be between 5 and 5.5L for optimal driving, 15L is literal V8 territory lmao you are not getting that on a 1.5 DCI
Wow. There is so much emphasis on mileage, but nobody tells us what making that a priority does to your engine. You have just changed my driving style. Thank you!
Same goes for very light oils, and many other things done to modern cars. The thinking is like having a "qualifying" engine for a race, that is meant to be really fast for one lap or pass, and blow up. It doesn't benefit the consumer or the environment or anything else to require that myopic approach.
The best way to save money is to not buy new cars. Don't buy anything showy, because you're paying for the looks. In the UK driving a small diesel car is way more economical than public transport if you only have a few miles to go each day. I had a Vauxhall Corsa 1.3 diesel a while back, and normal driving never gave less than 50 mpg, so the 12 mile round trip was less than £2. And even now it would still be less than £3 per day.
Thank you for this video. What I find very interesting about it, is that my late father told me this when I got my first Motor Bike, Sixty years ago. I bought a second-hand 250cc bike and it rattled, so I stripped it down and my father explained the ridge around the top of the cylinder and the fractured big end shells, which were caused by the engine never having been run at high revs and the bike being forced to accelerate from low revs, whilst in high gear. When driving his car, my father would take advantage of good roads and 'race' the engine at regular intervals. I helped him strip the car's engine at 85,000 miles. All he replaced, were the pistons, big ends and valves, as there was little wear. I made a point of following his advice since, especially after I bought my first car. Russ. Hampshire.
@@lassepeterson2740 That was a strategy my dad used when low on fuel 😂. Still he managed to get to the gas station on an almost empty tank. And barely any money since he had to go for the paycheck in the city.
i burned out a poorly constructed Mitsubishi manual transmission with low RPM driving .does not slap enough grease around and burned the bearings out, so now i keep the sucker always above 3000 RPMs. I was stunned when the tranny shop just said "known issue with the tranny"
I have Audi a3 2lt tdi it has suggested gear. I always ignore as I think it labours the engine. It’s supposed to be fuel efficient but I ignore and still get 60mpg.
Yeah, that kind of thing is to help the fleet average mpg for the gov't regulations. They don't care if it wears out your car faster. All the better, actually!
@@davidellis8141 Those suggestions always make me laugh, ain’t no way I’m going to labour the engine just for economy. My diesel often tells me to change from third to fifth, to which I generally laugh out loud.
I'm an American, and I insist on owning/driving cars with manual transmissions. I usually drive in a rather "spirited" manner, so low-rpm driving generally isn't something I do. But I definitely found this video interesting and I will endeavor to avoid wide-open-throttle in high gear at normal highway speeds when overtaking a slower vehicle. I'll endeavor to downshift even when when I might not have in the past. Thanks!
A redline each day, keeps the mechanic away. If you own an older diesel with injection pump and EGR valve, you will know driving at low rpm will ruin it.
This can be considered ancient knowledge. We all knew this concept in the 60s. Lugging an engine under load was never a good idea. Find the midrange for your engine. Ignore the tach, go by feel
Yup. In a lot of cars you can feel where the engine is comfortable. The engineers have optimized the engines dampened resonant frequency to transmit the fewest vibrations right around the point where the engine is at its most efficient. Although a lot of higher end cars have so much cabin vibration damping and/or drive by wire systems that hide the engines vibrations from the driver.
I drive a Volvo with a 1.6 diesel that my dad drove like this all the time before me. The car ran like absolute garbage when I got it, but after a year of hitting 3k rpm on pretty much every single drive, it's running better than ever.
As a Mechanical Engineer and enthusiast mechanic, i learnt a lot here about the actualy reasons to avoid lugging engines! Great video. My BMW 730d and BMW 520d both have 220,000 miles on the clock, both get used through the full RPM range and get excellent oil analysis results.
I've been saying this for years and no one listens, despite me being a qualified and very experienced automotive engineer, who's had to fix the problems caused by this. Actually with some cars, driving at these low RPMs might not be the most economical for mpg either.
Thanks for the clear explanations. I notice that when i drive my Mazda 3 2008 harder it runs smoother at idle too. Italian tune ups are the way to go. You can also have fun without breaking the speed limit. I pay for the best fuel and the best oil & despite the engine having high mileage their is never any smoke.
_" I notice that when i drive my Mazda 3 2008 harder it runs smoother at idle too. Italian tune ups are the way to go...."_ 100% confirmation bias, guaranteed...
Known as the Italian Tune-up. Own a C6 Corvette and all this transmission does is shift, pretty much always 1500-2000 RPM. It does get excellent fuel economy and main reason I bought it. Trust me I do open-up this engine.
My car turns at 1500rpm at 60mph in 8th gear on highway driving. With the ZF8HP it can shift in non-sequential manner. I once saw my transmission shift from 8th to 2nd to take evasive action while on the road.
Powerband recommendation is based on full throttle loads. Just drive your vehicle with light throttle loads. This wont overfuel your cylinders and on modern diesel engines you wont overfuel because the computer wont let it ,it will only give just the right amount of fuel
Three things came to mind watching this great video: 1. Paul Frere (race driver) always recommended to drive your engine at or above 1/3 red-line. 2. Saving fuel with low RPM accelerating is based on the engine consumption map that suggests driving with high load (NOT full throttle) at low RPM is most efficient. There even was a BMW advertisement in Germany in the late 70s explaining this in detail. 3. I still own my father's car (1972 Opel Commodore B Coupe GS with the 2.5 twin carb engine). In the manual for that car Opel writes: "If you have knocking due to carbon build-up, go on a 150km high speed Autobahn drive". A manufacturer recommended "Italian Tune-up" 🙂 Also, I am now a subscriber to this channel.
2:53 minor correction. Too high of a gear makes it more difficult for the engine to move the vehicle. I bike a lot and if I don’t shift down a couple gears on steep inclines I have more trouble gaining speed on a bike. A lower gear reduces the stress since the engine (or your legs when you’re riding a bike) can operate at a higher speed and more effectively move the vehicle without added stress.
Excellent. I've 300,000 km Passat. Guilty as charged. Low revs for economy. Cost me a flywheel last year, and Diesel Particulate Filter this year. A truck driver warned me about that faint vibration you get when you accelerate at low revs. He said that's when the damage is being done.
Thanks, that´s exactly the point. If you rev that low that the vibrations increase then you are doing harm. If you find a torque/rpm diagram of the engine with specific efficiency values then you can look for the "island of best efficiency". It usually is around medium-low rpm and high but not maximum torque. The rpm where this island is should also be best for reliability. High efficiency means little friction and little vibration losses, so it´s just a healthy state of operation for the engine.
The situation with DPF equipped diesels is unique. I have a 2017 Mitsubishi Triton automatic with just short of 125,000 km on the clock. When I retired and moved to a rural area it was easy to drive for fuel economy. I was doing just that, avoid the freeway and cruise the scenic backroads at 80 to 90 kph, however DPF faults began to occur and having them rectified / reset and oil changes [high crankcase level] cost much, much more than any incremental fuel saving. I changed to regular freeway use at 100 /110 kph and the issue appears to have been resolved. I never "lug" an engine, that is Barbaric.
@@gregorymalchuk272 [A] And ruin the engine [B} Pretty hard to lug an engine with an auto. [C] Diesels over fuel at high loads and low RPM, fuel only is regulated, there is no throttle body = effectively a rich mixture and more soot.
Been lugging the same VW TDI for 18 years with no engine issues. Although that's what old diesels were made for. Quickly noticed the VNT turbo didn't like that driving style. It would quickly start dropping into limp mode above 3,000 revs. Because the turbo vanes get stuck. So it gets the occasional blast above 4k to help clear them out.
All these websites and government advisories telling you to drive slow and preserve fuel. They don't care about engineer wear and tear because that's on you but emissions is what they car about. Thanks for the advice and pushing out solid info.
VERY important and well done video! I guess most people have never thought about it. For many years now I avoid driving my Audi Diesel below 2.000 rpm. Before that, I used to drive it at 1.200-1.400 which seemed to clog the costly particular filter much too fast. I also rev it to the redline every now and then, seemingly making the car run faster and cleaner. It now has 190.000 km on the clock without any engine repair.
Expert here. There's a saying. The sweet spot. That is the rpm range every motor has where it runs the best. The lowest rpm in that range is used in cruising, maintaining a constant speed. The highest rpm in that range is for extreme acceleration, also know as redline. That should only be done after engine has reached normal operating temperature. Ideally you never exceed that redline rpm, no matter what Scotty says! Most cars run very well at 2200 rpms. Find out what your lowest rpm is for cruising, then never run your engine lower than that. If you really want to know how hard to push on your gas pedal, put a hard boiled egg under your gas foot. If you crack your egg, you are now pushing down too hard!
Also a good reason not to go WOT at low rpms is the damage it causes to the gearbox, the small teeth that actually engage the gear and hold all the force slowly wear out. For example on diesels if you want to accelerate in 5th or 6th gear going below 2k rpm, it will sooner rather than later cause damage, because the engine has the torque and strength, but the gearing is way off to smoothly pull away, also at low speeds the transmission oil won't efficiently get to the 5th or 6th gears, this is a big issue with VW T4, T5 and even T6 transmissions, and also some 5 speed toyotas, usually Rav4. Great video, even though I feel like I know these things, it's always nice to learn more from knowledgable people!
forgot to mention that 1. Hot blow by gasses push out the oil between the piston rings and burn off oil , especially oil scraping ring that wil clog up. 2. oil needs to seal off the pistonrings. At low rpm oil is not able to maintain this seal. Mind that at tdc and bdc piston speed =0, at low rpm time enough to lose fluid pressure. In addition we use low piston rings tension and low viscosity oil like 5w30 C2 or 0w20. These oils can easily push out between surfaces (also bearings) 3 oil needs to clean the engine and at low rpm there is less flow through the engine and piston rings can not be cleaned by the oil. 4 higher service intervals makes it harder for the oil to do it's job. A extra oil change at 1/2 the interval cost less than a complete engine overhaul. Speeding up piston speed (higher rpm) will prevent problems.
Yes but higher engine speed automatically means more friction and wear bc more force means more friction (also true with lugging) so where is the balance between fast enough so the engine can function properly and slow enough that you aren’t constantly revving it out and causing extra wear
@@whatsomeonesaidwastaken9216 he means between 2000-3000 rpm, which is the sweet spot most engines are designed to work on. Lugging is done below 2000.
Sir: Great discussion & accurate. I grinned when you were talking about lugging. Some years ago I had a truck (I beg your pardon....I meant a "lorry" (grin) , that had a 16 litre , 500 hp diesel in it, & the torque available was huge (I disremember the figures) but I used to smile when pulling a long , steep grade, when I allowed the RPM's to drop to 1200 rpm & the engine would hold that speed. I did NOT make a practice of this, but from time to time I would watch the pyrometer, the "boost" gauge, & of course the tach. As soon as I saw the pyrometer start to climb, I downshifted. I own a 3/4 ton 4X4 pickup with a Cummins 6BT 215 hp, with a turbo & a 6 speed gearbox. I bought the truck new in 97, & it has over one & a half million miles on it & still going strong. The torque peak is about 1700 rpm's & that is where I drive it (100 kph/60 mph) . I have subscribed & I pushed the "like" button. Cheers! from the windswept hinterlands of Alberta Canada
Modern automatic transmissions are also programmed to keep the engine rpm below 1500. I drive my car with the transmission in sport mode maybe 80% of the time. Keeps the rpms in a good window
I've bought and sold a few cars in the last couple of years, and I 100% agree, I bought a 1 owner Daewoo Lanos on 44K miles, that belonged to an older gentleman who I think must have driven it very gently, as the crank case pressure was ridiculous and the performance was down, a bit of enthusiastic driving later and it sorted itself out though. I also bought a Vauxhall Tigra on 53K miles, that had been owned by an older lady who never went over 20 in it, I put it in for the MOT and all three emissions readings were in the red and it was burning oil, same again, drove it at about 4000RPM for well over half an hour, it had stopped burning oil and the emissions were in the green, I think the piston rings must have gotten stuck with carbon and the extra heat and pressure from a good thrash manage to loosen them. I will never let a car sit below 1750RPM now because the damage it does outweighs the convenience of not having to change gears constantly, and before someone mentions gearbox and clutch wear, proper driving has a negligible effect on either of these
My Grandad bought a brand new Suzuki Alto in 2004. In 2012 when he died it had only done 8000 miles, just from heading into town once per week to collect his pension and go shopping. The engine was in a terrible state, wouldn't run smoothly and reluctant to rev. A good motorway run and italian tune up improved it a lot.
This is the explanation I've been waiting for for years - many thanks! The bicycle comparison really makes it clear and the other explanations hit home. My cars are both automatics. I don't understand why people want electronics to control everything in the car but not the most basic thing - gear changing! Modern cars can change gears faster and smoother than most drivers!
An engine is most efficient when it is at its maximum torque. We used to have these ''infomercials'' here in the Netherlands, promoting ''the new driving'', where you are told to shift between 2000-2500rpm... I always said; Yeah, maybe in a diesel, but not in a gasoline car...
Thats not 100% correct. For instance modern downsized turbo petrol engines which is every 2nd car almost have peak torque at around 1,750-4,000 rpm range (depends on engine ofc, can be 1500-3500 etc). If you will go lets say 90 km/h at the highest gear you will be under 2k rpm. If you push the pedal all the way down you will hardly accelerate even if you have peak torque. You will need to downshift at least 2 gears. In general, turbo petrol engines will have good acceleration at 3,000+ rpm, non turbo petrol engines need much more rpm for good acceleration, at least 4,000. Turbo diesels will have good acceleration from 2,000-2500 rpm but are dead once you hit 4k.
@@blackwidow7804 Depends also if it has a lot of power/torque in general to compensate, for exemple a sport-ish car or bike can handle simple acceleration fine just in peak torque, right ?
After installing an EGT gauge in my car, I completely changed my driving style. You will be amazed to see how much the temperature raises when being in the false gear. Higher RPM often decreases temperature whereas too low RPM will skyrocket your EGT's.
When the needle is nearer to E than my pay is to my account I go back to the "short shifting" that I watched endurance touring cars drivers use to delay a pit stop..... but when I leave then petrol station on pay day suddenly I'm Colin McCray
Came upon this randomly, I didn't understand what lugging meant when you mentioned it, and I didn't even know the term existed. My father, who's been a driving instructor in the army 30 years ago or so, always told me to drive the car with rpms appropriate to the gear im in. Don't drive under 2-4k rpm if I'm in 3rd or 4th gear or drive with really high rpm, just listen to the engine, cause if you don't you're going to damage it and even break the crankshaft and damage other components And I've been doing it for 2 years now and my cars are in the condition they were when he gave them to me as a gift. I have 2 cars, I have a 2005 1.7 cdti opel corsa and a 2004 fiat panda minivan. I'll definitely remember this video and the information
IT all makes sense, one more factor to add, if you drive low RPM, and use your car for short distances most of the time. This is a killer. Engine never gets through that heating cycle, and over the time, TAR and Carbon starts to build in it. I have seen that with a BMW of my friend, who drove the car for grocery shopping only, i.e. short distances, he was low RPM fan. His car had engine issue so unique, BMW took his car for case study, they interviewed him on his driving habits, and fixed the engine for free. It is an extreme case, but certainly gives the idea, that Manufacturer design the cars and engine by keeping normal driving habits in their calculations, that engine shall go through all kind of RPM scenarios. if you are not driving "normally" be ready for surprises !
We bought a nice Mk7 Fiesta from a lady who was stopping driving. When we got it the engine had a slightly strange sound on startup which I ignored, but about a year after we had the car the piston slap sound became much more noticeable especially in the cold weather - I am convinced lugging caused this. Engines that have been ragged tend to be much nicer sounding...
I bought a Chrysler town and country. The former owner drove on econ mode. The engine was running horrible. But after engine flush and patrol cleaner an 6000 km high RPM driving it runs perfectly again. So you are so right!
I have a 1990 Mercedes-Benz 300SE, and the speedometer has small dots that show me how fast I can go before upshifting the automatic transmission. Jay Leno has talked about 'delayed shifting' an automatic transmission as it keeps the RPMs in the mid range where the engine works best. I believe it saves gas as the car has a vacuum gage, labled 'economy', and delayed shifting keeps the vacuum down, and I don't use the breaks as often while enjoying a more sporty driving experience.
Good advice. I'm a North American with an AWD Ford EcoSport 2.0 duratec engine. Automatic transmission. Almost all the miles I put on it are city. Stop and go. The transmission in regular Drive mode makes it lug around town. I have found on my own that driving in Sport mode gets me up to 2 more mpg. It revs higher at whatever posted speed limit, and has less difficulty accelerating from a stop. A higher RPM, but much less stress. It actually 'likes' to rev. If I go on the interstate/freeway to 70mph, I will go ahead and have it in regular Drive mode. It's enough speed to not be lugging the engine. It's a small engine carting around a surprising 3,500 lbs with 149 lbft of torque at a HIGHER rpm for such a small vehicle in the states. So, it's best to take stress off the engine and rely more on its 166hp than to count on any low-end torque...that it doesn't have.
Oh, to think we grew up with Mk1 Escorts with horrible fixed choke carbs. That taught you everything. Modern fuel injection and engine management cover up too many of our sins. Strangely it turned out the rules for maximum fuel efficiency turned out to be the same rules for maximum power. The rule is to "follow the engine" - no point throwing fuel at the engine if it can't burn it. It needed air flow. Buuuuut - if you are doing it to save fuel, that is darned tiring on your ankle. So the next best thing was stick it in cruise control and juggle the setting around the mpg display. But yes, change the oil, change the air filter, and never never push a cold engine! . . .
Very well explained. I am very mechanically savvy and avoid driving in low rpm unless the load is very light. However, I missed quite a few points that you make (water, oil pump rpm etc). Well done!
This is something that drives me nuts when it comes to transmission shift logic, including DCTs. I don't want to be in top gear at 40 mph. If I need to do an evasive (acceleration or cornering), nothing good is going to happen. I usually select my own gears. I'd prefer a manual but for the fact that they are slower than a good DCT and no longer have the edge on fuel economy. Plus, on the rare occasion I feel lazy, I can go full auto.
My car was blessed with an owner's manual, to which I referred for the suggested shift points. It truly is packed with information, that owner's manual is. 😉
There is nothing wrong with running low rpm at highway speeds so long as you're on flat terrain. When accelerating or highway driving in hill country, it's a terrible idea.
I have three Nissan Sentras with a CVT. Here in the suburbs of Dallas, Texas, I do a lot of driving at 40-50 mph (65 to 80 kph) at about 1,200 to 1,600 rpm’s. I accelerate slowly and I’ve never had an engine problem.
One thing is ECO on lower RPMs, one thing is full gas on low RPM (2nd gear does not count) and going uphill on low RPM 😢 rip engine edit: what most peeps dunno tho is the fact that the most fuel savings come when you hit the max-torque-range and sustain at that. Obviously the lowest spectrum of that BUT every engine has it set a little bit different SO this is the no.1 reason when to go to the "brake" or DYNO
If you just grabbed any normal car and operated it's engine at the rpm which has peak torque, you'd be running the engine too high rpm for the load, decreasing fuel economy and increasing fuel usage. Only on really underpowered cars like kei cars could this make some sense. Driving at 30 kmph while the engine is at 2000 rpm is not fuel efficent, 1000-1500 is more efficent under low power demands because you aren't wasting extra fuel on friction, even though you are running the engine at a lower thermal efficency. Once you're at highway speeds though, you will need the extra power, and moving at a higher speed is a positive for fuel economy, until the thermal efficency peaks or drops off, and the friction of the engine rpm and air resistance starts to negatively effect fuel economy. With a perfect transmission, you will get better fuel economy at lower speeds than higher speeds simply because of air resitance, friction and thermal efficency occuring at different engine loads, rpm and manifold preassure. But no, we have inperfect transmissions, driveshafts, bearings and engines. So, we get especially bad efficency at lower speeds because both wasted engergy braking and accelerating quickly, and engines being at too high rpm for the speed you are going. It's why often times an automatic transmission can get better fuel economy than a manual transmission, because it's always upshifting when it can and wants to to get the desired fuel economy or power. Someone driving a manual might maintain 2500 rpm through a roundabout, because who's going to upshift twice while navigating intersections while observing the road for hazards while steering, indicating, multitasking etc.
MOST EXCELLENT Presentation --- An engineering definition of SET rpm: A standard from Mechanical & Automotive Engineering for 'rotating equipment': A CONSTANT ~70% of designed *maximum 'operating' rpm* will typically yield maximum in-service life. Such has been "The Rule of Thumb" since the ~1930s. Rx: Use your cruise control as much as possible, NEVER rapidly accelerate a COLD engine; and most important - - - - - DO NOT 'LUG' an IC engine. For the 'modern' engine with (mandated) LOOSE TENSION PISTON RINGS ... change the oil ON TIME (or earlier) if most of your driving is at constant 'highway' speeds: and, at 50% of the recommended oil change interval if most of your driving is 'stop and go' (city) driving.
@@ryans413 technically the easier gear for pulling away/slow speeds is "lower" if you're considering gear ratio, conversely, the harder gear for faster roads is "higher".
Why anybody would be surprised by that concept is baffling to me, it's been a thing forever with cars owned by older folks who puttered back n forth and the engine getting carbon build up on everything. The easiest way to clean a engine up like that is install a water injection system or put it on high idle and start spraying water in the carb or throttle body but gradual is better because you can dislodge a large chunk and crack a piston. When I was at the vocational college for automotives a guy had a 69 mach 1 with a 351 Cleveland that had been chugged around for years and the owner gave it a hot supper all the way to the school which was 2 hours non stop through middle of no where and in the shop it started banging, the teacher thought someone had dropped a bolt down the carb but no one had, it was carbon chunks breaking free, he misted water down the carb and it got worse before it got better and black water was just puffing out the tailpipes but eventually it quieted down and ran fine, It was clanging and banging pretty good during the process, even then I thought it was a risky move he could have easily cracked a piston. Excessive short trips raise hell with engines too, if they rarely get up to operating temp they build up a lot of carbon deposits and sludge and moisture in the engine, gotta get them things hot... People think I'll run a cold thermostat for more power but same deal engines need to reach a certain temp to operate properly.
That reasoning is truly valid if you're talking about VERY LOW rpms. Like near idle all the time. Also, the general reasoning doesn't apply to all cases: there are engines and engines, ones more suited for a good efficiency band at very low rpm, others very bad for running even at modestly low rpms. Like a small engine block with a long piston stroke could be very well suited for cruising and rolling reaccelerations at 1500rpm, a small stroked heavy vehicle should never see anything under 2500rpm.
Low RPMs are horrible for the clutch and flywheel. There’s a reason you see so many diesels with clutch replacements at less than 200k miles and so many reports of DMF failure shortly after remaps, especially in cases of people remapping for economy. I knew a guy who killed a clutch in 3 years by trying to save fuel, despite all the warnings he had. It also punishes the crank shaft and connecting rods. But people are so desperate to save a few pennies or get a dopamine buzz from seeing an outrageously high fuel economy reading.
There is no wear to Clutch except when you are using it. Clutch wears when taking off and on shifts. More wear when upshifting on hills. Unless the clutch is slipping it doesn't matter what the rpm are when disengaged.
My dad taught me this when I was going up a hill in his 1.0 car in 2nd gear, but he was not a mechanical engineer, just a civil engineer, but he knew what kind of strettes that put the engine in
When I started my career in 1974 I bought a brand new Mustang 2. Four cylinder overhead cam engine. I started My driving career with old school straight sixes and V8 Engines. I drove the Mustang At low rpm for about 6 months. The engine developed catastrophe symptoms. Luckily Ford replaced the engine under Warranty. The service manager Had a talk with me and educated me about why I Needed to use the engine at Higher rpm . It was strange at First but I learned the engine Thrived on RPM' s. Go ahead Wind it up. Within reason.
I agree with your end conclusion, but it's factually incorrect that gasoline engines are *less* efficient at low rpm driving. Higher rpms will come at the cost of fuel efficiency. The only thing that can happen to cause a higher fuel usage has to do with knock. Low rpms come with the increased risk of knock, which can destroy your engine. To avoid this, some ECUs inject more fuel with the purpose of dropping the temperature in the cilinder, especially the head. This sounds counter intuitive, but a liquid evaporating will take away heat from its surroundings. So excess fuel (that cannot be burned because of lack of oxygen) evaporating in the cilinder will actually cool down the cilinder to avoid knock from happening. Engineering Explained has some videos on this topic 😊
@timobreitscheidt9382 absolutely! But it adds considerable complexity to the engine: separate injectors, separate water tank, water lines, etc. Fuel is already there, so that's what's they're using.
Can we say that the correct gear would mean the RPM where engine have peak torque/ performance. Meaning that's where the engine is comfortable the most?
That's a difficult thing to do legally with a supercharged V8, unless you are on a race track. My Jag sits around 1000 to 1500 rpm unless I am accelerating hard or doing motorway speeds. I do like to let it rip though.
@@ericrawson2909 people say this peak torque all the time but most of the time the public road conditions don't let you use the load, so are you going to sit at 4500 rpms and light throttle drinking more fuel just to be ready for the occasional pounce around a slower car or steep hill? The most efficient conversion of fuel to power is usually around 2500 rpm at 80% load, but if you're not using the load, lower the rpm further for more efficiency. The logic to the peak torque is well the engine is making the most force from the fuel, forgetting that the fuel per stroke is not constant even with the pedal to the floor, but rises slightly with increased rpm. This is why I don't bother with enormous engines but get one that is more appropriately sized for public road use, rather than one that starts to get into the bottom of the power band at 120 mph, and is drinking away fuel just to be fun for the 1% of the driving time that the road is clear, and the rest of the time it's in great grandma mode.
I regularly run my old, owned since new, 2006 Honda Civic on the highway in third gear, at 5000 rpm, for a few minutes after it's already warmed up. Specifically to clean out both the engine and the catalytic converter. So far so good. The engine runs perfectly.
Tip. Go down hill in same gear as you would use if going up the same hill. But, but, but, instead of pressing the brake to slow the car. change down a gear or 2. What does this do? A it stops fuel being burnt. B, it increases engine revelutions and turns the engine into a compressor. C is saves brake and tyre wear. D it is good for the environment. E it gives you greater control of your car. I once came down a hill on a motorway doing 80 KmPH or 50 mph in 3rd gear. i overtook 2 other drivers braking hard. I was in full control of my car. The other driver beside me had a look of fear on his face.
Depends on the engine. A two stroke engine hates coasting, because with no oil squirters you run the engine with no oil. Diesles don't typically have a butterfly valve so no compression braking, and some cars have an exhaust brake, and most semi truck motors have a jake brake. Your advise is fantastic for someone with a petrol engine car, but pretty redundant for other engines.
Before engaging engine braking take a quick glance at rear view mirror and make sure vehicle behind u is not following too closely. Engine braking does not turn on the brake lights.
Generally speaking you are correct. I lug my 7.0 L V8 all the time. But every engine has its own “lug” range which is throttle and gear dependent. This car idles in High gear at 45 to 50 miles an hour and will cruise at 80 miles an hour under 2000 RPMs which works fine on the highway. All that said I agree with about 99% of what’s been said. Even though this motor produce well over 300 ftlbs of torque at 2000 rpm (wheel TQ - tuned on chassis Dyno) you still don’t want to go WOT in high gear at that low RPM. You can feel/hear the engine complaining through its labored acceleration. Jeremy Clarkson demonstrated this in his one gear pull to something like 175 mph and you can clearly see the engine isn’t happy and you understand exactly what being discussed. Vintage top gear around 2007 or 2008. Here video of me lugging my car now: 2007 Z06 LS7 - Well Mannered Until Not... TSP Stage 3 LS7S ua-cam.com/video/7SKkCBZvNfs/v-deo.html
I scrolled down to see if any other LS 'vette owners had commented. It's difficult to "lug" an engine that has a very flat torque curve in a lightweight car.
I drive at extreme low RPM with my CVT, around town in 25 MPH limit I speed up at 1,250 RPM. Around 40 MPH limits I speed up around 1,500 to 1,600 RPM. And on the 50-60 MPH roads with stop lights I speed up around 2,000 RPM. Merging onto the freeway I go around 2,500 RPM. The CVT should prevent lugging, but carbon build up is possible.
Sounds like a special case. CVT vary the rpm seamlessly so you technically should be at the right rpm all the time 🤔 Carbon buildup is engine design, direct injection and EGR which is overall 👎
@@extralock1045 Always throws me off when I get a loaner hybrid or something. It's a different driving style for sure. And my fuel economy absolutely suck because I'm driving it like I drive mine. Doesn't work 😄
Your cvt is doing technically ideal thing peoples brain just cant comperhend that. And with carbon... If you just do 2miles trips reving wont help, if you drive on open road and highway sometimes it will reach operating temps for dpf for example anyways soo..
@@Boz1211111 I regularly drive on the highway for 100, or 200 miles, sometimes 300 miles. I usually stay at 55 MPH. Only go over when going down a 6% grade. Cruising at 55 MPH I'm at about 1,900 RPM. Going up a 6% grade, I'm at 2,300 RPM with the AC off, 2,700 with the AC on. I regularly go up mountains too. I have a house on an 8,500 foot tall mountain. So I regularly go up to work on it, or drive up for fun. I tend to hold the car at 1,900 or 2,000 RPM goin gup the 40 mile long hill. That gets be between 30, and 35 MPH. I just take all the turn outs to let everyone by. But with 78 horse power, it does quite well!
Very interesting insights. Thanks for the detailed explanations on how high load at low revs affects the engine components. I learned a few things here. I used to be under the impression that high rpm = bad. I remember when I got my 1st car 20 years ago, my Father was appalled when I accelerated past 4k. He insisted that those sort of revs will "destroy" my engine. In more recent years I learned that this wasn't entirely correct, I heard about the Italian tune up and all the problems with diesels that are kept at low revs. I've had 2 diesels since, and never had issues with carbon or blocked dpfs. I think the trick to keep diesels healthy is regular drives above 2.5k rpm, mixed with some pulls up to 4k+ I think manufacturers aren't helping with longevity with their dash lights telling you to upshift at anything above 1800rpm (as is the case on my current car)
@@Athaion0 I think I had the R18 in my Integra. Bulletproof and loved to rev, yeah for sure. I miss that car. My K24 isn't as rev-happy but it will go up there on demand no problem!
I have a Mazda 3 2018 manual petrol. I soo use the aid from the dashboard, where it indicates accordingly as to WHAT gear I should be in. My reading of that is - the engine is reading WHAT gear it wants to be in. Thank you for your advice.
My 1.4 Diesel can go up a pretty steep hill in 5th gear at 2000 RPM with 50% throttle going around 50 - 55 mph. It doesn't have any more power available though, even with my foot to the floor it wouldn't go much faster. 4th gear would probably be the better gear (RPM would be around 2500 rpm) but it gets up in 5th fine without labouring. It only has about 68bhp.
Having just built my engine for my Chevrolet Suburban I would have loved to see this video. I planned my build with the understanding that at about 3500 rpm the vehicle would be doing about 55-60 miles per hour which is pretty much the normal range of speed in the areas that I drive. I also pull trailers or am driving off road where the lower speed of the vehicle is more common. That puts my engine with the cam and internals that I put in it were planned for the 1500 to 5000 rpm range of the cam. There are so many things that you mention that most people do not even consider them. This was a great video.
@@awebuser5914 The reason I figure it is that high is because that is where the old engine ran for this speed. The new engine is designed for toeing and going off road which will also require low speed from the transfer case and higher speed on the engine.
Rule of thumb, Idle to 2,000RPM is for driving. Idle to the rev limiter is for accelerating, engine braking and high speed. You won't bend it If you don't send it Send it! Unless you drive a 1.3L Yaris, then you need to change up gear 50RPM before over rev cut, because pathetic torque to weight ratio.
Torque to weight ratio has no engineering meaning. Only power to weight ratio appears in the physics for acceleration. P=Fv, F=ma therefore P=(ma)v and thus *acceleration = Power / (mass x velocity)* ... torque does *NOT* appear. Torque is mainly just a function of the capacity and geometry of the engine (undersquare or oversquare, 2-valve or 4-5-valve airflow characteristics). Good torque at low rpm, really just means good power at low rpm. Power is the fundamental rate the engine can convert chemical energy to kinetic energy. Torque is just an intermediate crankshaft twisting force due to the geometry of an internal combustion engine. A rocket or jet engine can create power directly from thrust without using torque.
So... I've been unintentionally damaging my engine? I always thought lower rpm meant less wear. This explains everything... Explains why I needed a new engine at 23k miles and why the same issue that caused me to get the new engine is happening again... And I was blaming the manufacturer...
You should start this video by stating that most of what you are talking about here applies more to small cc turbo charged engines. For example NA 4.0 V8 won't really care about it but a 1.6 or 2.0 turbo charged petrol engine will be affected by this, especially LSPI at low revs and high throttle. Also diesels generally don't give much of a dam about this either.
@@foxy126pl6plenty of diesel like older land cruiser have peak torque at only 1200 rpm. It's because diesels don't rely on spark, they combust at max compression it's less an issue as no timing.
I've always tried to avoid lugging my motors in anything that I ride or drive. I try to keep the RPMs above 2000. And in my turbocharged car, above 2500. It's never good to lug a motor. If you have to dump a bunch of gas into it to get it going faster, better to downshift. Lugging a motor puts a lot more force on the tops of the pistons which wears out bearings quicker. I'm 62 years old and have always gotten a lot of miles out of my vehicles. Regular maintenance and driving correctly are both key. Stay away from too high or too low of rpms.
I noticed this on my motorcycle (Suzuki Vstrom 650) . I was doing as the manual suggested & rode at around 10 mph per gear aka at 60 mph (100 kph) just hitting 6th gear. My computer said I was getting around 48 mpg. The sweet spot in the torque curve was another 1k rpm though. Staying in 5th gear at 60 mph put me right at my 5200 rpm sweet spot. I did not reset the trip meter with about 6k miles on it. This started to raise my mpg & throttle response noticeably. After a week or two of daily riding raised my mpg to about 52. That means nearly 8% better mileage, another full gear above my usual commute speed with more responsive & smoother higher speed acceleration. The wind speed became my cap in 6th gear around 75 mph before the efficiency started to drop off again.
This is interesting, but I don't understand your text, please clarify. "another full gear above my usual commute speed". Is 5 above 6? Is a gear above speed? Does speed mean gear?
![🚫10 Driving Habits That KILL Your Car 💥[Warning]](http://i.ytimg.com/vi/NONXE1_lE5Q/mqdefault.jpg)
As an Engineer I just can say THANK YOU for that good video about this topic!
I saw a ton of videos about this topic (and rpm ranges in general) and most of them seem to consist of hear say and "what my old grandfather told me"-stuff.
It highly depends on the car, usually diesel engines are more happy with low rpm than gasoline engines but lugging them all the time will give you higher blow by rates in general.
Furthermore as you've noted, you don't save fuel just by driving in low rpms, you're saving fuel by driving in the rpm range where the engines has its top torque output.
As an example you've got the 1.9 TDI (engine code 1Z) from VW. This turbo diesel engine has a max. torque of 202Nm at 1850rpm. Driving it below that makes only sense if you don't need power, if you're gliding the road. If you need power for e.g. an overtake then you want to be in the range of elasticity of the engine. It is the range between max torque and max power. In case of our example, it is between 1850rpm and 4000rpm (max power there), the redline is at ~4500rpm and the ECU drastically decreases the power at about 4250~4300rpm. I usually shift down to reach about 2200 to 2500rpm to start the rapid acceleration, it pulls good enough to shift to the next gear in the range of 3500rpm, which sends it back to about 2500rpm, and gives the opportunity for a second push. I rarely hit the redline, since the power rapidly goes down after 4100-ish rpm. Which isn't uncommon for older turbo diesel engines, since they protect themselves from excessive temperatures of the exhaust gases, which gets more dangerous if the rpms are higher due to the higher amount of gasses (mass there of).
If you are a hyper miler or someone who really wants to know how to do it right in your car, get the torque diagrams. You can find them on the internet for the most cars and engines. Be sure to validate the revision (date of construction), version and engine code of the engine you have in use.
Safe roads and all the best,
Bruce
Thanks my friend, I really appreciate the kind words of support, I had no idea this video would be so popular especially as there are fewer drivers with a manual than ever, but it does seem that there are lots of drivers with bad habits out there.
And let's face it we could all do with developing mechanical sympathy for our engine.
I didn't explain a few points as well as I'd have liked in this video so I will revisit this topic in future to clarify those.
@@torquecars You're welcome :)
Congratz for your video took up, it was a ton of work for sure :D
Ha, yes, you couldn't stiff everything in one video, like a lecture at the University. Better split them up and give every video a critical of the topic.
I'm looking forward to, until then, take care and safe roads!
I also have 1.9 tdi, love that engine. I didn't know about diagrams and max torque, but just from feeling I knew that a little bit below 2k is sweet spot for the engine.
And then my father drivers 1.6 tdi on 1.2k rpm - it hurts me to watch that, to listen to those low frequency vibrations (btw, what is that low frequency sound when driving low rpm under load?). Told him many times that it's not good nor for the engine, nor for the mileage, but he just didn't listen to me. Nothing I can do about it.
@@BruceCarbonLakeriver you know, I'm not gonna try to counter what you've said, since it seems completely true and I am by far not well acquainted with engine design. But I do believe that low or high rpm don't really matter in my 55hp, 3 cylinder 1.2 Liter polo. It just always tries to force an immovable object into motion XD
I drive a 2L TDI for work and my buttdyno told me that it delivers most power at 1750-2500 rpm, full throttle above or below that range just makes the van vibrate/shake. And from what littl' I know about engineering is that vibration is the enemy of any mechanical system. Also, from a mileage point of view, if your vehicle starts shaking when throttling, that enermy isn't going into moving you forward, but side to side instead, so ease off a littl'
Dudes in 100k mile civics living at a constant 10k rpm and only going 25mph, it all makes sense now.
Well my motorcycle 125cc 4 stroke has a bit more than 40K KM and now to do a full fuel tank I need to top up almost the full engine oil in like 3 times and that's the reason of being 95% or more always in high RPM but due to the lack of power it just needs full accelerator and full rpm all the time sadly ☹
The thing is it barely even smokes unless at like RPM cut just a very tiny bit, its like the damn oil is just evaporating from inside the engine FFS, also not a single drop of oil ever dropped either, the whole engine is all dry from the outside.
@@guily6669mine had the same issue, tho it just happened at 250k kms. It was stuck oil rings.
180k miles on mine and 7k rpm is my daily 😂
@@Athaion0 7K??? mine goes a lot to 115000 rpm LOL it's the rpm cut, it doesn't have a rpm gauge but it's around there... but like 9 - 10K is more constant.
@@jojomarujo8704 wow that thing lasted quite long, it isn't a 125cc with a crap single piston??
A Porsche engineer once told me: "If you love your pistons, never accelerate at low revs.'"
The Porsche salesman told me the opposite.
@@VictorMaxol Salesman wants to sell a new car.
@@mirasetrin3273 that was the joke 😅
It makes sense that you should never give full throttle at low revs. The cylinders will then become much too hot, which can cause the rings to crack, as Subaru also advises. Now that rarely happens in Europe, because the petrol is of much better quality, but if you live in the USA, be careful..
My foot told me the opposite😂
I pay for my whole dang tachometer, so i'm gonna use all the numbers in it.
@@UNBIASEDCOMMENT **proceeds to push the engine until all lamps light up**
@@ianclose123 I'm not in favor of using the entire range of the oil pressure or water temperature gauges
@@snowcrest7863 my car has no meters for these, only has fine and too much... I've used used both haha
🎯🔥💥
@@Squee7e this reminds me of my last track day. Barely made half of the lap without check engine light and power loss
The TLDR: don’t lug your engine, redline it once a day, don’t excessively idle, MAINTAIN YOUR VEHICLE!!
Never in my life have I redline an engine. Usually I change gears at around 3000 RPM. If I need more, at most, I will change at 5000 RPM.
I will never redline my SPI. The thing sounds like it’s ready to quit at 2,500-2,800 rpm. I’m good on taking that chance 😆maybe if I had the Zetec or Duratec
@@CasualGaming76 i have a duratec, we had to change the cam bc it overheated on me and i would bever redline that shit ever in my life
Welp time to redline the R18 Civic
Redline a day? Redline every shift! put that clutch to use! :D
Low rpm is not a problem IF you don't require power and torque from the engine.
Very true
Exactly this. When up to speed and in the right gear, very little torque is required.
@@johntheodosiou7248 what a genius. I realize I don't need to start my car if I am not moving
Then you are not lugging..
@@johntheodosiou7248 uou have an emergency and need aceleratr to avoid an accident, you will lose time to drop a gear
Lugging has ruined more engines than revving, rule of thumb, if you press down on the accelerator and your vehicle dose not accelerate easily then you need to down shift and if you are giving more gas to maintain your speed you need to down shift, it is just that simple. How ever revving your engine to high rpms with no load on it is not good for it either.
There's limits to it throttles are throttles not a switch there's controll to it if it's juddering and banging to much load for the rpm lift low rpm doesn't destroy engines neither does using revs it'd mostly just down to your load variable tbf most things just die from black death and lack of servicing never seen grannieing break anything even when it's come to giving a car it's first kicking after 90k miles 😂
Why is revving your engine to high rpms with no load on it no good? There's no load.
Just get an automatic. Problem solved.
@@tofuguru941 i think that full throttle up to redline going downhill is where there's no load, and very bad. Uphill there is engine load. Or when towing. But I'm not sure what the poster exactly meant.
@@tofuguru941your engine is meant to be loaded up. Maybe not 100% load at 1k rpm, but 90% of the time your engine is under load, so I'm going to assume they build it to be under load. But I'm not sure really. It could be the speed at which the rpms rise. Not enough time for the oil to make it to critical components.
My mother got so lazy at shifting. She would drive through town without down shifting, doing 35mph in 5th gear. She killed two or three cars like this. I finally told her to stop driving manuals, and buy automatics.
Automatics aren't necessarily the best answer. I drive an auto which is very reluctant to change down; if left to its own devices it would slog up hills all day at below 1000rpm, so I frequently find myself manually selecting a lower gear to ease the load on the engine.
@@saxon-mt5by as a co-driver on a garbage truck that's automatic,i agree.
The automatic is perfect anywhere else for the type of vehicle it is, but hills are problematic as it struggles to select a proper gear.
@@Deceit-hx7ey Would lifting off or pressing down on the pedal for a moment make it downshift. Automatics are "dumb" computers that don't want to shift if you don't change the throttle input.
@@modarkthemauler there is actually a semi-mechanic mode on the truck that is engaged with a button on the wheel, there you can go higher or lower by 1 gear.
So that kinda solves the hill and automatic issues lol.
@@Deceit-hx7ey Hooning my flappy paddle garbage truck!
Diesels in particular need to be driven like the police are chasing you..(DPF, EGR and rxhaust cleaning). My grandad told me Diesels are designed to work, not rest…Also they need a good run to build heat and regular services..to keep them fit..
Just like the human body !
Diesels are true tanks if serviced regualy, They are literally designed to haul heavy loads over long distances. Our nanny state should never had declared war on them.
same with 2 strokes engines
@@Xxfootball70xX less moving parts
Not if you delete all that baloney
Many modern cars encourage this sort of behaviour. Auto's change up too early to keep the engine at low RPM, and many manual cars with gear change indicators often make you change up too early. Like many eco features they seem to prioritise a few MPG over engine longevity.
Yup espescially annoying in vans. To overtake or go up a hill with load you have to rev up the engine and it keeps flashing "shift!"
So this is more a case of bad driving habits than actual low rpm driving.
So true
Yes, few engines suffer from doing low rpm for extended periods with little to no load on them, (with the exception of the badly designed oil pumps out there). Keeping low RPM and pressing hard on the throttle will add wear and tear, although the degree with which this happens will vary from engine to engine.
@@torquecars There are many vehicles that have worn out prematurely because they had extended idling which is why Police package vehicles frequently have upgrades designed for extended idling. Newer vehicles have variable displacement or even electrically operated oil pumps to negate the necessity of these special packages.
I only use 2nd and 4th gear in VW Golf . I rarely ever use 1 3 5 6 Is that considered a bad habit ?
@@lassepeterson2740 depends on road, your gearing, and speed limits. Your clutch probably doesn’t like starting in 2nd all the time, but not a big deal. More wear when people rest their door on clutch
I’ve been red lining my Ford fusion every day for 304,000 miles and counting. My engine seems to really like it honestly. As long as you change your oil and coolant on time I think it’s actually good for the engine
I’ve been driving for 40 years and although I’m no engineer I have pretty much driven the way you describe in this video - ie I use light throttle at low revs and while I do drive for economy on average I do indeed approach the red line from time to time and on a twisty road I will usually hold onto a lower year which is also safer as it gives more control and better response. Cars that I have owned have consequently remained healthy into high mileage and tend to burn very little engine oil.
How many RPMs are we talking when you say low revs?
@@Xenon777_ I would say anything below 2K is low and even around 2K I would only gradually increase the throttle rather than stamp on it. For full throttle it’s best to be close to the mid-range torque. Obviously this varies from engine to engine - I have a 1.4 TSi which is a low pressure turbo.
My opinion is that a gasoline engine car can be used between 2000 and 4000rpm with no problem if one wants some torque. Over 4000rpm, one is either looking for power, or for engine problems. Below 2000, if you are not accelerating to reach your usual speed, you are decelerating to stop the car or looking for a car park place; anything other than this is lugging the engine, and looking for mechanical problems too.
In a diesel engine, I would say the torque band is between 1000 and 2500rpm. Over 3000, you are looking for power (on an engine supposedly full of torque) or, once more, looking for technical problems
@@oscaraurelio8869 my personal non professional opinion on diesel engines as i have the most experience with diesel engines is
Allways ride the torque curve
My car peak torque is at around 2000rpm as most diesel engines
I ride it at around 2500 since its a bmw and its really revs happy, if i need to drive at under 2000rpm that means im in too low of a gear
While thats the case with my revs happy engine
My ford focus is not really revs happy and its made for economy in mind i change at 2000rpm and ride it around 1800 fo 2200 depending on conditions
Oscar is right for the average engine.
I've always found keeping a 4 or 6 cyl avg compression gasoline motor between 2000 and 4000rpm 90% of the time to equal long engine life and best fuel usage. I have always been able to shift from 5th to 4th or 3rd in time to achieve a pass, a climb or an engine braking as I live in the mountains with steep switches.
My wife can't seem to get comfortable with a clutch so she has a 6 sp electric automatic...it responds very quickly to throttle input in a pass or climb... I do not ever sense lugging or knocking.
I typically keep cars since 1990 to 200k or 250k, and sell them because I have just grown tired of them after 15 to 20 years...or the subcomponents start failing with age...wiring, electric windows, switches, trim, alternators, pumps, etc...
Every redliner I know was always having motor work done on a regular basis over 0 to 100k miles...or replacing the motor or engine. They may not be related...as it may just be the enthusiast race fan personality that desires constant car attention. When I drove a BMW, there were lots of trim and body parts available in junkyards because the car had blown a motor in hard kid driving or dumping it into 2nd at high speeds.
Have run a 1990s Ford for over 300k miles, nearly all of the time changed gear between 2000-2200 RPM. Engine still sounds sweet, 5k oil changes have helped
My oils nice and clear Ford been driving it about like this. 2.3L Ranger
@@CarlSmith-bs4qx still running the old Ford pushrod engines. If you maintain them properly you won't need to buy another one.
Not an issue as its an older somewhat low rpm engine, and they peak on torque way down in the basement by like 2500 or even earlier.
@@MrTheHillfolk they are also very simple to repair if ever needed. As long as you don't let it overheat it will keep running.
I've had 3 Hondas (Civic, Integra, Accord Coupe) manuals, and I changed gears at around 3K RPM all the time, and NEVER had any engine issues either...
It’s ok to use lower RPM when car is still cold because cold oil doesn’t flow as quickly, but after it warms up it’s completely fine to use the whole RPM range every once in a while
All modern oils these days flows immediately, we're talking seconds. It's not exactly going from molasses to water in viscosity change. Just look at the oil flowing from a new bottle very liquid. Also specifically made to flow just fine in sub zero temps hence the W-rating. So at -20°C I can see a slight need to not overdo it the first 5 minutes but the oil is indeed flowing or any engine would be toast at every cold start
@rosen9425 that is very true, But just because the oil is flowing it still doesn’t mean it is up to operating temperature. Which is why it is a good idea to take it easy for the first few minutes before driving the car aggressively.
@@FGNi-em9sb
Engine oil doesn't have to be at operating temperature to lubricate, it does that all the time. The enemy of lubrication is old oil. The older the less lubrication properties are left. It's why have to change it.
All engine oils in a normal cars are multigrade oils, designed to operate at various temperature intervals. There's a cold and hot viscosity rating meaning the oil properties change as the heat increases. Excessive heat does break down the oil so abnormal heat over 100°C or so is much worse than freezing temps until extremes of -40°C or so.
A funny BMW note I read in a manual said something like this.
Engine break in: keep the speed below 200 kmh the first 1500 km
What is driving aggressively and why is that a parameter to take into account at all?
Sounds like abnormal behavior subject to a mentality attitude correction more than babying the engine oil in a car 🤔
Most modern engines are alloy with steel stretch bolts clamping the head down. They don't reach full clamping force on the head gasket until full operating temperature is reached so it is good to avoid wide open throttle operation until warmed up to avoid head gasket failures.
@@rosen9425 mentality attitude correction? Lol ok Dr. 🤣
I have owned a V8 since 2007. It idled with the AC on during hot weather and heater in cold weather for years. It has 309k and runs great.
Thanks for the video. I am a retired motor tech. I know you say not to criticise you but after a lifetime of using the terminology of the higher the numerical number of the gear directly equates to the higher the ratio. But you say lower gear which as I said after a lifetime grates on my sensibilities. I was taught to drive ( especially on the open roads ) to keep the revs between 2 - 4 K rpm. Over 4K and you start to increase engine wear. If you are travelling around town at 30 it is better to be in 3rd gear rather than 4th for the same reasons you gave of less strain on pistons and crankshaft. Strangely fuel economy is better as well. Keep posting.
@@ChrisPatrick-q6k same
This is a bit outdated, though. Just a detail, some cars have gear selection suggestions. If you are not or barely under load, the gear selection suggestion, suggests rpm around 1200. Also, most modern (normal day to day use) engines have almost maximum torque above 1500 rpm to 4000 rpm. So it will almost never be necessary to exceed 2500 rpm unless you tow something heavy.
You will carbon up your engine if you drive by those gear suggestions. You might save fuel, at the cost of the engine.
Cheers buddy, I try to use terms that Most of the general public will interpret correctly, but totally dropped the ball there trying to simplify. I think though I can probably get away with more technical concepts if I explain them fully.
I knew this would produce a debate. As I said in my original post I have been driving for 52 years and know what I'm talking about. The guidance I gave applies equally now as to then . It is necessary to keep strain on an engine to a minimum. Lugging has wrecked thousands of engines. I've had a car for up to 20 years and when I had to scrap it through rust the engine was still perfect.
This video can be shortened by saying. Keep your engine in the torque range of your paticular engine and your engine will be happy
Would it matter for cvt? Genuine question. My cvt likes to keep the rpms low when accelerating. It accelerates just fine just wondering if I need to start throttling more for more rpms or not.
@@needtau4138 not really, it’s an automatic you can’t control it you can only control the throttle that way
Without saying how you find out about the design philosophy and the specs of the phase space of engine wear, fuel economy, RPM and power output.
No, that would be way too unclear.
@@letsgo2510 That would mean taking his word with no explanation and no variables entered into the single statement.
It literally takes checking the instant fuel consumption to understand that lugging your engine actually uses more fuel than the correct rpm, especially going uphill.
@@25myma luckily, I drive an auto that knows better than me about when to shift lmao
Not the case in my car actually. (1.2 TSI)
What engine do you drive?
@@nielsonderbeke8507 k9k (renault 1.5 dci) in my case. It's very obvious in hill climbs when I downshift, going from ~1500rpm to ~2300... goes from about 15-16l/100km to ~12-13.
I guess it has to spray a lot more at those low rpms to keep pulling the weight up. In level driving it doesn't change much.
@@25myma but you say on hill climbs, which is like 2% of the time for the avrage person. What happens if u go on a straight road and go from 1500rpm to 2300 with a lower gear. Does your fuel consumption go down again?
@@25myma looool 15L/100km in the 1.5DCI ?? What the actual fuck are u talking about that can't be right, even if u keep driving at 3000rpm for 4 hours at 120kmh it would never get past 7L, ideally it would be between 5 and 5.5L for optimal driving, 15L is literal V8 territory lmao you are not getting that on a 1.5 DCI
Wow. There is so much emphasis on mileage, but nobody tells us what making that a priority does to your engine. You have just changed my driving style. Thank you!
Same goes for very light oils, and many other things done to modern cars. The thinking is like having a "qualifying" engine for a race, that is meant to be really fast for one lap or pass, and blow up. It doesn't benefit the consumer or the environment or anything else to require that myopic approach.
The best way to save money is to not buy new cars. Don't buy anything showy, because you're paying for the looks. In the UK driving a small diesel car is way more economical than public transport if you only have a few miles to go each day. I had a Vauxhall Corsa 1.3 diesel a while back, and normal driving never gave less than 50 mpg, so the 12 mile round trip was less than £2. And even now it would still be less than £3 per day.
@@wordreet what's the highest you got? Imm guessing you are from the UK
@@wordreet does that include insurance, road tax and servicing?
I have seat leon 2.0 tdi and get 60mpg some times more if I'm really trying. This is a 13 mile trip and cost me about £1.40 Diesels are great
Are you including any potential parking fees into that?
short trips in a diesel? yikes
Thank you for this video. What I find very interesting about it, is that my late father told me this when I got my first Motor Bike, Sixty years ago. I bought a second-hand 250cc bike and it rattled, so I stripped it down and my father explained the ridge around the top of the cylinder and the fractured big end shells, which were caused by the engine never having been run at high revs and the bike being forced to accelerate from low revs, whilst in high gear. When driving his car, my father would take advantage of good roads and 'race' the engine at regular intervals. I helped him strip the car's engine at 85,000 miles. All he replaced, were the pistons, big ends and valves, as there was little wear. I made a point of following his advice since, especially after I bought my first car. Russ. Hampshire.
Low revs are not an issue, it's labouring the engine that jerks the transmission. If you want to save fuel accelerate briskly and then coast.
@@bikeman123 Its counterintuitive but the math support this statement. Accelerate and then coast to next stop saves fuel.
It is possible to accelerate gently without lugging the engine, though. Just use the proper gear.
Accelerate , then turn the engine off until you need power again .
Best comment
@@lassepeterson2740 That was a strategy my dad used when low on fuel 😂. Still he managed to get to the gas station on an almost empty tank. And barely any money since he had to go for the paycheck in the city.
i burned out a poorly constructed Mitsubishi manual transmission with low RPM driving .does not slap enough grease around and burned the bearings out, so now i keep the sucker always above 3000 RPMs. I was stunned when the tranny shop just said "known issue with the tranny"
What year and model? Have a 09 Lancer GTS with a 5 speed on its second transmission, and really want it to be its last
I have Audi a3 2lt tdi it has suggested gear. I always ignore as I think it labours the engine. It’s supposed to be fuel efficient but I ignore and still get 60mpg.
Thing is they suggest changing up gear going up hills 🤷
Yeah, that kind of thing is to help the fleet average mpg for the gov't regulations. They don't care if it wears out your car faster. All the better, actually!
@@davidellis8141 Those suggestions always make me laugh, ain’t no way I’m going to labour the engine just for economy. My diesel often tells me to change from third to fifth, to which I generally laugh out loud.
@@danmaycock9238 Had a Fiat Punto that sometimes suggested going up a gear while I was in sixth ... :)
@@Paul58069 To perform a magic trick then?
Great tip. I’ve always driven this way - Not to low not to high, when the engine feels like it’s doing easy work your in that sweet spot.
I'm an American, and I insist on owning/driving cars with manual transmissions. I usually drive in a rather "spirited" manner, so low-rpm driving generally isn't something I do. But I definitely found this video interesting and I will endeavor to avoid wide-open-throttle in high gear at normal highway speeds when overtaking a slower vehicle. I'll endeavor to downshift even when when I might not have in the past. Thanks!
A redline each day, keeps the mechanic away.
If you own an older diesel with injection pump and EGR valve, you will know driving at low rpm will ruin it.
This can be considered ancient knowledge. We all knew this concept in the 60s. Lugging an engine under load was never a good idea. Find the midrange for your engine. Ignore the tach, go by feel
Yup. In a lot of cars you can feel where the engine is comfortable. The engineers have optimized the engines dampened resonant frequency to transmit the fewest vibrations right around the point where the engine is at its most efficient.
Although a lot of higher end cars have so much cabin vibration damping and/or drive by wire systems that hide the engines vibrations from the driver.
Yeah it also helps if you can actually hear the exhaust note to tell when to shift rather than looking at the rpm gauge.
Yes by the feel. Find the rpm with the minimal to no cabin vibration. That's the rpm is the sweet spot
@@nomore25 cabin vibration hat? must be an american thing
I drive a Volvo with a 1.6 diesel that my dad drove like this all the time before me. The car ran like absolute garbage when I got it, but after a year of hitting 3k rpm on pretty much every single drive, it's running better than ever.
In the old days cars hated low RPM acceleration. Try full throttle on a Ford Cortina at 1500 RPM and the whole car would vibrate.
As a Mechanical Engineer and enthusiast mechanic, i learnt a lot here about the actualy reasons to avoid lugging engines! Great video.
My BMW 730d and BMW 520d both have 220,000 miles on the clock, both get used through the full RPM range and get excellent oil analysis results.
Thanks for watching!
I've been saying this for years and no one listens, despite me being a qualified and very experienced automotive engineer, who's had to fix the problems caused by this.
Actually with some cars, driving at these low RPMs might not be the most economical for mpg either.
Thanks for the clear explanations. I notice that when i drive my Mazda 3 2008 harder it runs smoother at idle too. Italian tune ups are the way to go. You can also have fun without breaking the speed limit. I pay for the best fuel and the best oil & despite the engine having high mileage their is never any smoke.
_" I notice that when i drive my Mazda 3 2008 harder it runs smoother at idle too. Italian tune ups are the way to go...."_ 100% confirmation bias, guaranteed...
Known as the Italian Tune-up. Own a C6 Corvette and all this transmission does is shift, pretty much always 1500-2000 RPM. It does get excellent fuel economy and main reason I bought it. Trust me I do open-up this engine.
My car turns at 1500rpm at 60mph in 8th gear on highway driving. With the ZF8HP it can shift in non-sequential manner. I once saw my transmission shift from 8th to 2nd to take evasive action while on the road.
Powerband recommendation is based on full throttle loads. Just drive your vehicle with light throttle loads. This wont overfuel your cylinders and on modern diesel engines you wont overfuel because the computer wont let it ,it will only give just the right amount of fuel
Three things came to mind watching this great video: 1. Paul Frere (race driver) always recommended to drive your engine at or above 1/3 red-line. 2. Saving fuel with low RPM accelerating is based on the engine consumption map that suggests driving with high load (NOT full throttle) at low RPM is most efficient. There even was a BMW advertisement in Germany in the late 70s explaining this in detail. 3. I still own my father's car (1972 Opel Commodore B Coupe GS with the 2.5 twin carb engine). In the manual for that car Opel writes: "If you have knocking due to carbon build-up, go on a 150km high speed Autobahn drive". A manufacturer recommended "Italian Tune-up" 🙂 Also, I am now a subscriber to this channel.
2:53 minor correction. Too high of a gear makes it more difficult for the engine to move the vehicle. I bike a lot and if I don’t shift down a couple gears on steep inclines I have more trouble gaining speed on a bike. A lower gear reduces the stress since the engine (or your legs when you’re riding a bike) can operate at a higher speed and more effectively move the vehicle without added stress.
Yeah he conflated the two at the start when talking about hyper milers too
@@thingyee1118 Lol, did you just conflate the word conflate?
Excellent. I've 300,000 km Passat. Guilty as charged. Low revs for economy. Cost me a flywheel last year, and Diesel Particulate Filter this year. A truck driver warned me about that faint vibration you get when you accelerate at low revs. He said that's when the damage is being done.
Thanks, that´s exactly the point. If you rev that low that the vibrations increase then you are doing harm.
If you find a torque/rpm diagram of the engine with specific efficiency values then you can look for the "island of best efficiency". It usually is around medium-low rpm and high but not maximum torque. The rpm where this island is should also be best for reliability. High efficiency means little friction and little vibration losses, so it´s just a healthy state of operation for the engine.
The situation with DPF equipped diesels is unique. I have a 2017 Mitsubishi Triton automatic with just short of 125,000 km on the clock. When I retired and moved to a rural area it was easy to drive for fuel economy. I was doing just that, avoid the freeway and cruise the scenic backroads at 80 to 90 kph, however DPF faults began to occur and having them rectified / reset and oil changes [high crankcase level] cost much, much more than any incremental fuel saving. I changed to regular freeway use at 100 /110 kph and the issue appears to have been resolved. I never "lug" an engine, that is Barbaric.
Lugging would increase your EGTs and help burn the soot out of the DPF.
@@gregorymalchuk272 [A] And ruin the engine [B} Pretty hard to lug an engine with an auto. [C] Diesels over fuel at high loads and low RPM, fuel only is regulated, there is no throttle body = effectively a rich mixture and more soot.
My 15 Golf TDI is diesel. The power band is much lower RPM. I don't lug it ever but it RPM at 60 mph on the highway is about 1500-1600.
Been lugging the same VW TDI for 18 years with no engine issues. Although that's what old diesels were made for. Quickly noticed the VNT turbo didn't like that driving style. It would quickly start dropping into limp mode above 3,000 revs. Because the turbo vanes get stuck. So it gets the occasional blast above 4k to help clear them out.
Yes. Video is misleading. Engine is fine. Its only accesories that might benefit from higher rpm
All these websites and government advisories telling you to drive slow and preserve fuel. They don't care about engineer wear and tear because that's on you but emissions is what they car about. Thanks for the advice and pushing out solid info.
Key note everyone! *use your gearbox*
VERY important and well done video! I guess most people have never thought about it.
For many years now I avoid driving my Audi Diesel below 2.000 rpm. Before that, I used to drive it at 1.200-1.400 which seemed to clog the costly particular filter much too fast. I also rev it to the redline every now and then, seemingly making the car run faster and cleaner. It now has 190.000 km on the clock without any engine repair.
Expert here. There's a saying. The sweet spot. That is the rpm range every motor has where it runs the best. The lowest rpm in that range is used in cruising, maintaining a constant speed. The highest rpm in that range is for extreme acceleration, also know as redline. That should only be done after engine has reached normal operating temperature. Ideally you never exceed that redline rpm, no matter what Scotty says! Most cars run very well at 2200 rpms. Find out what your lowest rpm is for cruising, then never run your engine lower than that. If you really want to know how hard to push on your gas pedal, put a hard boiled egg under your gas foot. If you crack your egg, you are now pushing down too hard!
Lol funny tip at the end, a shame that someone might do this and get into a bad situation from the egg liquids.
@@-aid4084 He did Say use a HARD Boiled egg, Not a raw or soft boiled egg. Then there is no egg liquids.
@@TapeManIT yeah my brain somehow missed that completely.
@@TapeManIT exactly. People will still not read it and use raw egg.
Also a good reason not to go WOT at low rpms is the damage it causes to the gearbox, the small teeth that actually engage the gear and hold all the force slowly wear out. For example on diesels if you want to accelerate in 5th or 6th gear going below 2k rpm, it will sooner rather than later cause damage, because the engine has the torque and strength, but the gearing is way off to smoothly pull away, also at low speeds the transmission oil won't efficiently get to the 5th or 6th gears, this is a big issue with VW T4, T5 and even T6 transmissions, and also some 5 speed toyotas, usually Rav4. Great video, even though I feel like I know these things, it's always nice to learn more from knowledgable people!
forgot to mention that
1. Hot blow by gasses push out the oil between the piston rings and burn off oil , especially oil scraping ring that wil clog up.
2. oil needs to seal off the pistonrings. At low rpm oil is not able to maintain this seal. Mind that at tdc and bdc piston speed =0, at low rpm time enough to lose fluid pressure. In addition we use low piston rings tension and low viscosity oil like 5w30 C2 or 0w20. These oils can easily push out between surfaces (also bearings)
3 oil needs to clean the engine and at low rpm there is less flow through the engine and piston rings can not be cleaned by the oil.
4 higher service intervals makes it harder for the oil to do it's job. A extra oil change at 1/2 the interval cost less than a complete engine overhaul.
Speeding up piston speed (higher rpm) will prevent problems.
Yes but higher engine speed automatically means more friction and wear bc more force means more friction (also true with lugging) so where is the balance between fast enough so the engine can function properly and slow enough that you aren’t constantly revving it out and causing extra wear
@@whatsomeonesaidwastaken9216 he means between 2000-3000 rpm, which is the sweet spot most engines are designed to work on. Lugging is done below 2000.
Thanks, from now on I'm not going to idle at red lights, will keep pedal to the metal
@@01lexe correct. I change oil at 3000 miles. And use only conventional oil.
This is why I always buy highway driven engines, they are at their peak power and efficiency always!
Sir: Great discussion & accurate. I grinned when you were talking about lugging. Some years ago I had a truck (I beg your pardon....I meant a "lorry" (grin) , that had a 16 litre , 500 hp diesel in it, & the torque available was huge (I disremember the figures) but I used to smile when pulling a long , steep grade, when I allowed the RPM's to drop to 1200 rpm & the engine would hold that speed. I did NOT make a practice of this, but from time to time I would watch the pyrometer, the "boost" gauge, & of course the tach. As soon as I saw the pyrometer start to climb, I downshifted. I own a 3/4 ton 4X4
pickup with a Cummins 6BT 215 hp, with a turbo & a 6 speed gearbox. I bought the truck new in 97,
& it has over one & a half million miles on it & still going strong. The torque peak is about 1700 rpm's
& that is where I drive it (100 kph/60 mph) . I have subscribed & I pushed the "like" button.
Cheers! from the windswept hinterlands of Alberta Canada
Modern automatic transmissions are also programmed to keep the engine rpm below 1500. I drive my car with the transmission in sport mode maybe 80% of the time. Keeps the rpms in a good window
Minor Hyper-Miler here. 260,000 miles on my 2009 Pontiac Vibe GT. Thx
I've bought and sold a few cars in the last couple of years, and I 100% agree, I bought a 1 owner Daewoo Lanos on 44K miles, that belonged to an older gentleman who I think must have driven it very gently, as the crank case pressure was ridiculous and the performance was down, a bit of enthusiastic driving later and it sorted itself out though. I also bought a Vauxhall Tigra on 53K miles, that had been owned by an older lady who never went over 20 in it, I put it in for the MOT and all three emissions readings were in the red and it was burning oil, same again, drove it at about 4000RPM for well over half an hour, it had stopped burning oil and the emissions were in the green, I think the piston rings must have gotten stuck with carbon and the extra heat and pressure from a good thrash manage to loosen them. I will never let a car sit below 1750RPM now because the damage it does outweighs the convenience of not having to change gears constantly, and before someone mentions gearbox and clutch wear, proper driving has a negligible effect on either of these
A clutch job is generally under 1000€. A new engine is at least 10 times that.
This is why I always buy highway driven engines, they are at their peak power and efficiency always!
My Grandad bought a brand new Suzuki Alto in 2004. In 2012 when he died it had only done 8000 miles, just from heading into town once per week to collect his pension and go shopping. The engine was in a terrible state, wouldn't run smoothly and reluctant to rev. A good motorway run and italian tune up improved it a lot.
This is the explanation I've been waiting for for years - many thanks! The bicycle comparison really makes it clear and the other explanations hit home. My cars are both automatics. I don't understand why people want electronics to control everything in the car but not the most basic thing - gear changing! Modern cars can change gears faster and smoother than most drivers!
An engine is most efficient when it is at its maximum torque.
We used to have these ''infomercials'' here in the Netherlands, promoting ''the new driving'', where you are told to shift between 2000-2500rpm...
I always said; Yeah, maybe in a diesel, but not in a gasoline car...
Thats not 100% correct. For instance modern downsized turbo petrol engines which is every 2nd car almost have peak torque at around 1,750-4,000 rpm range (depends on engine ofc, can be 1500-3500 etc). If you will go lets say 90 km/h at the highest gear you will be under 2k rpm. If you push the pedal all the way down you will hardly accelerate even if you have peak torque. You will need to downshift at least 2 gears. In general, turbo petrol engines will have good acceleration at 3,000+ rpm, non turbo petrol engines need much more rpm for good acceleration, at least 4,000. Turbo diesels will have good acceleration from 2,000-2500 rpm but are dead once you hit 4k.
@@blackwidow7804 Depends also if it has a lot of power/torque in general to compensate, for exemple a sport-ish car or bike can handle simple acceleration fine just in peak torque, right ?
After installing an EGT gauge in my car, I completely changed my driving style. You will be amazed to see how much the temperature raises when being in the false gear. Higher RPM often decreases temperature whereas too low RPM will skyrocket your EGT's.
When the needle is nearer to E than my pay is to my account I go back to the "short shifting" that I watched endurance touring cars drivers use to delay a pit stop..... but when I leave then petrol station on pay day suddenly I'm Colin McCray
Lol
@@Athaion0yup. If the light is red i go passed 4000 quite rarely
Came upon this randomly, I didn't understand what lugging meant when you mentioned it, and I didn't even know the term existed. My father, who's been a driving instructor in the army 30 years ago or so, always told me to drive the car with rpms appropriate to the gear im in. Don't drive under 2-4k rpm if I'm in 3rd or 4th gear or drive with really high rpm, just listen to the engine, cause if you don't you're going to damage it and even break the crankshaft and damage other components
And I've been doing it for 2 years now and my cars are in the condition they were when he gave them to me as a gift. I have 2 cars, I have a 2005 1.7 cdti opel corsa and a 2004 fiat panda minivan. I'll definitely remember this video and the information
IT all makes sense, one more factor to add, if you drive low RPM, and use your car for short distances most of the time. This is a killer. Engine never gets through that heating cycle, and over the time, TAR and Carbon starts to build in it.
I have seen that with a BMW of my friend, who drove the car for grocery shopping only, i.e. short distances, he was low RPM fan. His car had engine issue so unique, BMW took his car for case study, they interviewed him on his driving habits, and fixed the engine for free. It is an extreme case, but certainly gives the idea, that Manufacturer design the cars and engine by keeping normal driving habits in their calculations, that engine shall go through all kind of RPM scenarios. if you are not driving "normally" be ready for surprises !
Short distances were the issue, not the rpm driving.
@@imzjustplayinaye.
We bought a nice Mk7 Fiesta from a lady who was stopping driving. When we got it the engine had a slightly strange sound on startup which I ignored, but about a year after we had the car the piston slap sound became much more noticeable especially in the cold weather - I am convinced lugging caused this. Engines that have been ragged tend to be much nicer sounding...
I bought a Chrysler town and country. The former owner drove on econ mode. The engine was running horrible. But after engine flush and patrol cleaner an 6000 km high RPM driving it runs perfectly again. So you are so right!
I have a 1990 Mercedes-Benz 300SE, and the speedometer has small dots that show me how fast I can go before upshifting the automatic transmission.
Jay Leno has talked about 'delayed shifting' an automatic transmission as it keeps the RPMs in the mid range where the engine works best.
I believe it saves gas as the car has a vacuum gage, labled 'economy', and delayed shifting keeps the vacuum down, and I don't use the breaks as often while enjoying a more sporty driving experience.
I would add: not to blindly follow the "best gear" indicator on the dashboard.
@@EmilioBaldi these are so dumb. Made to advise bad drivers by giving them bad advice.
Good advice. I'm a North American with an AWD Ford EcoSport 2.0 duratec engine. Automatic transmission. Almost all the miles I put on it are city. Stop and go. The transmission in regular Drive mode makes it lug around town. I have found on my own that driving in Sport mode gets me up to 2 more mpg. It revs higher at whatever posted speed limit, and has less difficulty accelerating from a stop. A higher RPM, but much less stress. It actually 'likes' to rev. If I go on the interstate/freeway to 70mph, I will go ahead and have it in regular Drive mode. It's enough speed to not be lugging the engine.
It's a small engine carting around a surprising 3,500 lbs with 149 lbft of torque at a HIGHER rpm for such a small vehicle in the states. So, it's best to take stress off the engine and rely more on its 166hp than to count on any low-end torque...that it doesn't have.
Oh, to think we grew up with Mk1 Escorts with horrible fixed choke carbs. That taught you everything. Modern fuel injection and engine management cover up too many of our sins. Strangely it turned out the rules for maximum fuel efficiency turned out to be the same rules for maximum power. The rule is to "follow the engine" - no point throwing fuel at the engine if it can't burn it. It needed air flow. Buuuuut - if you are doing it to save fuel, that is darned tiring on your ankle. So the next best thing was stick it in cruise control and juggle the setting around the mpg display. But yes, change the oil, change the air filter, and never never push a cold engine! . . .
Indeed motorcaft carb's
Very well explained. I am very mechanically savvy and avoid driving in low rpm unless the load is very light. However, I missed quite a few points that you make (water, oil pump rpm etc). Well done!
This is something that drives me nuts when it comes to transmission shift logic, including DCTs. I don't want to be in top gear at 40 mph. If I need to do an evasive (acceleration or cornering), nothing good is going to happen. I usually select my own gears. I'd prefer a manual but for the fact that they are slower than a good DCT and no longer have the edge on fuel economy. Plus, on the rare occasion I feel lazy, I can go full auto.
A dct will shift from highest gear to one with most power available before you can blink, there’s no point in being in a lower gear.
My car was blessed with an owner's manual, to which I referred for the suggested shift points.
It truly is packed with information, that owner's manual is. 😉
There is nothing wrong with running low rpm at highway speeds so long as you're on flat terrain. When accelerating or highway driving in hill country, it's a terrible idea.
I have three Nissan Sentras with a CVT. Here in the suburbs of Dallas, Texas, I do a lot of driving at 40-50 mph (65 to 80 kph) at about 1,200 to 1,600 rpm’s. I accelerate slowly and I’ve never had an engine problem.
One thing is ECO on lower RPMs, one thing is full gas on low RPM (2nd gear does not count) and going uphill on low RPM 😢 rip engine edit: what most peeps dunno tho is the fact that the most fuel savings come when you hit the max-torque-range and sustain at that. Obviously the lowest spectrum of that BUT every engine has it set a little bit different SO this is the no.1 reason when to go to the "brake" or DYNO
If you just grabbed any normal car and operated it's engine at the rpm which has peak torque, you'd be running the engine too high rpm for the load, decreasing fuel economy and increasing fuel usage.
Only on really underpowered cars like kei cars could this make some sense. Driving at 30 kmph while the engine is at 2000 rpm is not fuel efficent, 1000-1500 is more efficent under low power demands because you aren't wasting extra fuel on friction, even though you are running the engine at a lower thermal efficency. Once you're at highway speeds though, you will need the extra power, and moving at a higher speed is a positive for fuel economy, until the thermal efficency peaks or drops off, and the friction of the engine rpm and air resistance starts to negatively effect fuel economy.
With a perfect transmission, you will get better fuel economy at lower speeds than higher speeds simply because of air resitance, friction and thermal efficency occuring at different engine loads, rpm and manifold preassure.
But no, we have inperfect transmissions, driveshafts, bearings and engines. So, we get especially bad efficency at lower speeds because both wasted engergy braking and accelerating quickly, and engines being at too high rpm for the speed you are going.
It's why often times an automatic transmission can get better fuel economy than a manual transmission, because it's always upshifting when it can and wants to to get the desired fuel economy or power. Someone driving a manual might maintain 2500 rpm through a roundabout, because who's going to upshift twice while navigating intersections while observing the road for hazards while steering, indicating, multitasking etc.
MOST EXCELLENT Presentation ---
An engineering definition of SET rpm: A standard from Mechanical & Automotive Engineering for 'rotating equipment': A CONSTANT ~70% of designed *maximum 'operating' rpm* will typically yield maximum in-service life. Such has been "The Rule of Thumb" since the ~1930s.
Rx: Use your cruise control as much as possible, NEVER rapidly accelerate a COLD engine; and most important - - - - - DO NOT 'LUG' an IC engine.
For the 'modern' engine with (mandated) LOOSE TENSION PISTON RINGS ... change the oil ON TIME (or earlier) if most of your driving is at constant 'highway' speeds: and, at 50% of the recommended oil change interval if most of your driving is 'stop and go' (city) driving.
He uses the term "low gear" when I'm sure everyone else would say "high gear ". Pretty confusing in a video majoring on rev range and gears.
Well technically the highest gear is the low gear because it’s not doing much gearing but I understand where people could be confused
@@ryans413 technically the easier gear for pulling away/slow speeds is "lower" if you're considering gear ratio, conversely, the harder gear for faster roads is "higher".
Yep he is confusing all drivers. Road signs and driving test low gear is gears 1,2,3 etc and high being 456
@@ryans413 you are confused
In my 6700lb supercrew F150 I never have to go past 2k rpm to accelerate under any condition. Love that torque.
Why anybody would be surprised by that concept is baffling to me, it's been a thing forever with cars owned by older folks who puttered back n forth and the engine getting carbon build up on everything. The easiest way to clean a engine up like that is install a water injection system or put it on high idle and start spraying water in the carb or throttle body but gradual is better because you can dislodge a large chunk and crack a piston. When I was at the vocational college for automotives a guy had a 69 mach 1 with a 351 Cleveland that had been chugged around for years and the owner gave it a hot supper all the way to the school which was 2 hours non stop through middle of no where and in the shop it started banging, the teacher thought someone had dropped a bolt down the carb but no one had, it was carbon chunks breaking free, he misted water down the carb and it got worse before it got better and black water was just puffing out the tailpipes but eventually it quieted down and ran fine, It was clanging and banging pretty good during the process, even then I thought it was a risky move he could have easily cracked a piston. Excessive short trips raise hell with engines too, if they rarely get up to operating temp they build up a lot of carbon deposits and sludge and moisture in the engine, gotta get them things hot... People think I'll run a cold thermostat for more power but same deal engines need to reach a certain temp to operate properly.
That reasoning is truly valid if you're talking about VERY LOW rpms. Like near idle all the time. Also, the general reasoning doesn't apply to all cases: there are engines and engines, ones more suited for a good efficiency band at very low rpm, others very bad for running even at modestly low rpms. Like a small engine block with a long piston stroke could be very well suited for cruising and rolling reaccelerations at 1500rpm, a small stroked heavy vehicle should never see anything under 2500rpm.
Low RPMs are horrible for the clutch and flywheel. There’s a reason you see so many diesels with clutch replacements at less than 200k miles and so many reports of DMF failure shortly after remaps, especially in cases of people remapping for economy. I knew a guy who killed a clutch in 3 years by trying to save fuel, despite all the warnings he had. It also punishes the crank shaft and connecting rods. But people are so desperate to save a few pennies or get a dopamine buzz from seeing an outrageously high fuel economy reading.
@@vxvii9069 why is it bad for the clutch and flywheel? Could you explain?
@@addi.1813 pretty sure not revving switching gears but preventing stall outs by riding the clutch accompanied by that low-rpm "rattle"
@@addi.1813because labouring the engine jerks the transmission
There is no wear to Clutch except when you are using it. Clutch wears when taking off and on shifts. More wear when upshifting on hills. Unless the clutch is slipping it doesn't matter what the rpm are when disengaged.
@@cruiser6260 But the Pressure plate is taking the beating at low rpm that's part of the clutch.
My dad taught me this when I was going up a hill in his 1.0 car in 2nd gear, but he was not a mechanical engineer, just a civil engineer, but he knew what kind of strettes that put the engine in
Jeremy Clarkson demonstrated the old Corvette Z06 can get from zero to 150 in one gear.
That engine has a ton of power so you're rarely gonna need to rev it that much in regular driving.
When I started my career in 1974 I bought a brand new
Mustang 2. Four cylinder overhead cam engine. I started
My driving career with old school straight sixes and V8
Engines. I drove the Mustang
At low rpm for about 6 months.
The engine developed catastrophe symptoms. Luckily
Ford replaced the engine under
Warranty. The service manager
Had a talk with me and educated me about why I
Needed to use the engine at
Higher rpm . It was strange at
First but I learned the engine
Thrived on RPM' s. Go ahead
Wind it up. Within reason.
I agree with your end conclusion, but it's factually incorrect that gasoline engines are *less* efficient at low rpm driving. Higher rpms will come at the cost of fuel efficiency.
The only thing that can happen to cause a higher fuel usage has to do with knock. Low rpms come with the increased risk of knock, which can destroy your engine. To avoid this, some ECUs inject more fuel with the purpose of dropping the temperature in the cilinder, especially the head. This sounds counter intuitive, but a liquid evaporating will take away heat from its surroundings. So excess fuel (that cannot be burned because of lack of oxygen) evaporating in the cilinder will actually cool down the cilinder to avoid knock from happening.
Engineering Explained has some videos on this topic 😊
Wouldn't it be cheaper to inject water instead of more fuel to prevent knock? Unburned fuel isn't good from what I know.
@timobreitscheidt9382 absolutely! But it adds considerable complexity to the engine: separate injectors, separate water tank, water lines, etc. Fuel is already there, so that's what's they're using.
That's why I like my Neon R/T, it has a very close range gear box so its always revving high no matter what speed I'm doing.
Can we say that the correct gear would mean the RPM where engine have peak torque/ performance. Meaning that's where the engine is comfortable the most?
That's a difficult thing to do legally with a supercharged V8, unless you are on a race track. My Jag sits around 1000 to 1500 rpm unless I am accelerating hard or doing motorway speeds. I do like to let it rip though.
I think it's correct yep :)
@@ericrawson2909 You can always be on a gear that you V8 ( even supercharged ) is the most confortable on. Just need tohave a very light foot.
@@ericrawson2909 people say this peak torque all the time but most of the time the public road conditions don't let you use the load, so are you going to sit at 4500 rpms and light throttle drinking more fuel just to be ready for the occasional pounce around a slower car or steep hill?
The most efficient conversion of fuel to power is usually around 2500 rpm at 80% load, but if you're not using the load, lower the rpm further for more efficiency. The logic to the peak torque is well the engine is making the most force from the fuel, forgetting that the fuel per stroke is not constant even with the pedal to the floor, but rises slightly with increased rpm.
This is why I don't bother with enormous engines but get one that is more appropriately sized for public road use, rather than one that starts to get into the bottom of the power band at 120 mph, and is drinking away fuel just to be fun for the 1% of the driving time that the road is clear, and the rest of the time it's in great grandma mode.
"Grannying the Car", love that expression, there's a lot of that going on round here.
if you ever rode a bike in high gear u notice how much more strain it puts on your legs, it's the same with an engine I'm pretty sure
@@alf3071 yes. How hard you push the pedals is your throttle input.
I regularly run my old, owned since new, 2006 Honda Civic on the highway in third gear, at 5000 rpm, for a few minutes after it's already warmed up. Specifically to clean out both the engine and the catalytic converter. So far so good. The engine runs perfectly.
Tip.
Go down hill in same gear as you would use if going up the same hill.
But, but, but, instead of pressing the brake to slow the car. change down a gear or 2.
What does this do?
A
it stops fuel being burnt.
B, it increases engine revelutions and turns the engine into a compressor.
C is saves brake and tyre wear.
D it is good for the environment.
E it gives you greater control of your car.
I once came down a hill on a motorway doing 80 KmPH or 50 mph in 3rd gear.
i overtook 2 other drivers braking hard.
I was in full control of my car. The other driver beside me had a look of fear on his face.
Depends on the engine. A two stroke engine hates coasting, because with no oil squirters you run the engine with no oil. Diesles don't typically have a butterfly valve so no compression braking, and some cars have an exhaust brake, and most semi truck motors have a jake brake.
Your advise is fantastic for someone with a petrol engine car, but pretty redundant for other engines.
Before engaging engine braking take a quick glance at rear view mirror and make sure vehicle behind u is not following too closely. Engine braking does not turn on the brake lights.
@@arrow2042
Good point.
Generally speaking you are correct.
I lug my 7.0 L V8 all the time. But every engine has its own “lug” range which is throttle and gear dependent. This car idles in High gear at 45 to 50 miles an hour and will cruise at 80 miles an hour under 2000 RPMs which works fine on the highway.
All that said I agree with about 99% of what’s been said. Even though this motor produce well over 300 ftlbs of torque at 2000 rpm (wheel TQ - tuned on chassis Dyno) you still don’t want to go WOT in high gear at that low RPM. You can feel/hear the engine complaining through its labored acceleration.
Jeremy Clarkson demonstrated this in his one gear pull to something like 175 mph and you can clearly see the engine isn’t happy and you understand exactly what being discussed. Vintage top gear around 2007 or 2008.
Here video of me lugging my car now:
2007 Z06 LS7 - Well Mannered Until Not... TSP Stage 3 LS7S
ua-cam.com/video/7SKkCBZvNfs/v-deo.html
I scrolled down to see if any other LS 'vette owners had commented. It's difficult to "lug" an engine that has a very flat torque curve in a lightweight car.
I drive at extreme low RPM with my CVT, around town in 25 MPH limit I speed up at 1,250 RPM. Around 40 MPH limits I speed up around 1,500 to 1,600 RPM. And on the 50-60 MPH roads with stop lights I speed up around 2,000 RPM. Merging onto the freeway I go around 2,500 RPM.
The CVT should prevent lugging, but carbon build up is possible.
Sounds like a special case. CVT vary the rpm seamlessly so you technically should be at the right rpm all the time 🤔
Carbon buildup is engine design, direct injection and EGR which is overall 👎
@@rosen9425 Yup! Always the right RPM. I just use very little throttle.
@@extralock1045
Always throws me off when I get a loaner hybrid or something. It's a different driving style for sure. And my fuel economy absolutely suck because I'm driving it like I drive mine. Doesn't work 😄
Your cvt is doing technically ideal thing peoples brain just cant comperhend that.
And with carbon...
If you just do 2miles trips reving wont help, if you drive on open road and highway sometimes it will reach operating temps for dpf for example anyways soo..
@@Boz1211111 I regularly drive on the highway for 100, or 200 miles, sometimes 300 miles. I usually stay at 55 MPH. Only go over when going down a 6% grade.
Cruising at 55 MPH I'm at about 1,900 RPM. Going up a 6% grade, I'm at 2,300 RPM with the AC off, 2,700 with the AC on.
I regularly go up mountains too. I have a house on an 8,500 foot tall mountain. So I regularly go up to work on it, or drive up for fun. I tend to hold the car at 1,900 or 2,000 RPM goin gup the 40 mile long hill.
That gets be between 30, and 35 MPH. I just take all the turn outs to let everyone by.
But with 78 horse power, it does quite well!
Very interesting insights. Thanks for the detailed explanations on how high load at low revs affects the engine components.
I learned a few things here. I used to be under the impression that high rpm = bad. I remember when I got my 1st car 20 years ago, my Father was appalled when I accelerated past 4k. He insisted that those sort of revs will "destroy" my engine.
In more recent years I learned that this wasn't entirely correct, I heard about the Italian tune up and all the problems with diesels that are kept at low revs.
I've had 2 diesels since, and never had issues with carbon or blocked dpfs.
I think the trick to keep diesels healthy is regular drives above 2.5k rpm, mixed with some pulls up to 4k+
I think manufacturers aren't helping with longevity with their dash lights telling you to upshift at anything above 1800rpm (as is the case on my current car)
High rpm is a engine killer, low rpm is a clutch and dm flywheel killer
Unless it's a honda K20
@@Bumblebeetle-di7sf Or Honda K24
@@rebeltvr6046my r18 loves 7k rpm
@@Athaion0 I think I had the R18 in my Integra. Bulletproof and loved to rev, yeah for sure. I miss that car. My K24 isn't as rev-happy but it will go up there on demand no problem!
tell that to highway driven vehicles!!! Nonsense
I have a Mazda 3 2018 manual petrol. I soo use the aid from the dashboard, where it indicates accordingly as to WHAT gear I should be in. My reading of that is - the engine is reading WHAT gear it wants to be in. Thank you for your advice.
5:45 you're right cause whenever i go uphill with 2000 on the revmeter and i add gas, it starts "choking" or twitching
@@paveljelinek772 with 2000rpm on uphill( slight uphill like most you can see on roads) the engine should not be choking. Your car lacks the power.
@@fer1306 my car has 102hp and it doesent choke at ~2200rpm going uphill in 4th so yeah
My 1.4 Diesel can go up a pretty steep hill in 5th gear at 2000 RPM with 50% throttle going around 50 - 55 mph. It doesn't have any more power available though, even with my foot to the floor it wouldn't go much faster. 4th gear would probably be the better gear (RPM would be around 2500 rpm) but it gets up in 5th fine without labouring. It only has about 68bhp.
@@Xenon777_ This basically means you choke it and SHOULD go 4th gear
I've done 5,500 up a hill quite regularly. Never overheats either.
Having just built my engine for my Chevrolet Suburban I would have loved to see this video. I planned my build with the understanding that at about 3500 rpm the vehicle would be doing about 55-60 miles per hour which is pretty much the normal range of speed in the areas that I drive. I also pull trailers or am driving off road where the lower speed of the vehicle is more common. That puts my engine with the cam and internals that I put in it were planned for the 1500 to 5000 rpm range of the cam. There are so many things that you mention that most people do not even consider them. This was a great video.
3,500 RPM would be insanely high for a Suburban (V8?) at 55-60 MPH.
@@awebuser5914 The reason I figure it is that high is because that is where the old engine ran for this speed. The new engine is designed for toeing and going off road which will also require low speed from the transfer case and higher speed on the engine.
Rule of thumb,
Idle to 2,000RPM is for driving.
Idle to the rev limiter is for accelerating, engine braking and high speed.
You won't bend it
If you don't send it
Send it!
Unless you drive a 1.3L Yaris, then you need to change up gear 50RPM before over rev cut, because pathetic torque to weight ratio.
lmao, it doesnt work. My 1.0L engine bogs down under 3000 rpm's
Torque to weight ratio has no engineering meaning. Only power to weight ratio appears in the physics for acceleration. P=Fv, F=ma therefore P=(ma)v and thus *acceleration = Power / (mass x velocity)* ... torque does *NOT* appear. Torque is mainly just a function of the capacity and geometry of the engine (undersquare or oversquare, 2-valve or 4-5-valve airflow characteristics).
Good torque at low rpm, really just means good power at low rpm. Power is the fundamental rate the engine can convert chemical energy to kinetic energy. Torque is just an intermediate crankshaft twisting force due to the geometry of an internal combustion engine. A rocket or jet engine can create power directly from thrust without using torque.
So... I've been unintentionally damaging my engine? I always thought lower rpm meant less wear. This explains everything... Explains why I needed a new engine at 23k miles and why the same issue that caused me to get the new engine is happening again... And I was blaming the manufacturer...
You should start this video by stating that most of what you are talking about here applies more to small cc turbo charged engines. For example NA 4.0 V8 won't really care about it but a 1.6 or 2.0 turbo charged petrol engine will be affected by this, especially LSPI at low revs and high throttle. Also diesels generally don't give much of a dam about this either.
Yeah, diesels are made for low rpm driving, they will be happy with anything above 1500rpm
@@foxy126pl6plenty of diesel like older land cruiser have peak torque at only 1200 rpm. It's because diesels don't rely on spark, they combust at max compression it's less an issue as no timing.
@@cruiser6260 - Along with that Diesels have no butterfly throttle valve.
You increase the fuel in order to increase the engine's rpm
I've always tried to avoid lugging my motors in anything that I ride or drive. I try to keep the RPMs above 2000. And in my turbocharged car, above 2500. It's never good to lug a motor. If you have to dump a bunch of gas into it to get it going faster, better to downshift. Lugging a motor puts a lot more force on the tops of the pistons which wears out bearings quicker. I'm 62 years old and have always gotten a lot of miles out of my vehicles. Regular maintenance and driving correctly are both key. Stay away from too high or too low of rpms.
0:24 Downtown Vancouver BC,Canada
I noticed this on my motorcycle (Suzuki Vstrom 650) . I was doing as the manual suggested & rode at around 10 mph per gear aka at 60 mph (100 kph) just hitting 6th gear. My computer said I was getting around 48 mpg. The sweet spot in the torque curve was another 1k rpm though. Staying in 5th gear at 60 mph put me right at my 5200 rpm sweet spot. I did not reset the trip meter with about 6k miles on it. This started to raise my mpg & throttle response noticeably. After a week or two of daily riding raised my mpg to about 52. That means nearly 8% better mileage, another full gear above my usual commute speed with more responsive & smoother higher speed acceleration. The wind speed became my cap in 6th gear around 75 mph before the efficiency started to drop off again.
This is interesting, but I don't understand your text, please clarify. "another full gear above my usual commute speed". Is 5 above 6? Is a gear above speed? Does speed mean gear?