I love it when people fly by me while I'm coasting, have to stop, and then they have to watch me fly by them because the light turned before I got to it.
Thats an amazing feeling. @Tony, very true. Always have to check the cross traffic before breaking the coast. Another hazard is that someone towards the back of the line will get the urge to cut me off so they can beat the first car at the light.
Jase, I coast to a red light also when possible so you dont always have to stop but more often then not some idiot(s) will race past and cut back in front of you then stop at the red light, then you have to stop too as they seem to have a slow reaction to the green , maybe checking their phone while stopped?
Engineering Explained right?! Or on the freeway with brake lights ahead and immediately on their brakes. Just coast... who knows, maybe you’ll never have to touch your brakes.. Save $ on both brakes & gas...
The reason realy is, atleast here in Germany, that the traffic lights have weight sensors. So if there is no car standing at the white line, the light will stay red for longer
Friends and family make fun of my 'old man' driving because I use these techniques whenever I can but are surprised that I maintain my speed limit on-ramps instead of braking like everyone else. They're even more surprised when my driving gets spirited in curves. Little do they know that I'm keeping myself entertained by challenging myself to drive efficiently.
I have never seen in my limited 5 years of driving experience ever seen anyone else coast in traffic like i do. Helps alleviate traffic and saves money and makes you calmer and more focused driver.
Yes, after 35 years of driving, 10 years bicycle commuting, and now a couple of years on a motorcycle commuting, I'm really not in a rush to go anywhere. If people are getting all uptight I'm VERY happy to move over and let them get as far away from me as possible. If someone wants to drive like a nut, there you go buddy you just move on past and get in front of me. WAAAY in front. Enough that I have time to brake before I come to the wreck you caused.
Exactly. Especially merging. I'll go off on a whole rant there if I get started. Idk why people think 6 inches off anothers bumper is the fastest way to move. @John. Agreed. I had to drive cross country a lot due to a job. Out of boredom, I'd play with the math to see what different speeds would save me time wise. Not worth it usually. A trick I like is someone hanging in your "blind spot" ( i have too many mirrors to have one) when you want to lane change. Blinker makes them be nice and slow down or be an ass and punch it. Either way, they are now out of your blind.
@@paulparoma rushing, pride, and a false sense of invincibility. That's what I think are the main culprits to the frantic, unsafe, racing mindset many drivers have...
Most satisfying thing is when one of those drivers that thinks he is cool overtakes you and eventually he just ends up standing still at a stop and you just cruise pass him.
I learned that first method with stop lights while driving motor scooters in town. If you slow down to give yourself more time before reaching the red light you have a better chance of reaching it still moving and you actually end up passing everyone that had rushed up to the light and then stopped. I have been especially interested in vehicle efficiency for about a decade and I can stand behind all your explanations. Even though I knew most of these I'm glad to hear it explained so clearly and with great detail.
@@TheCorecovers i mean you could do that but that's not really going to do much except make your synchros last longer. would be smoother, yes, but if you have synchros in your car then you should just use them. normal downshifting will be quicker and more practical in normal traffic.
Yeah but he still makes mistakes. The power used to fight fluid friction is indeed dependent on v², but the coefficient C_d (d for drag) is ALSO dependent on speed. Sometimes, you can increase your speed by just a little bit, and C_d gets divided by 2, which is nice. Also the power produced by the engine is not exactly the same as fuel consumption, because the efficiency ratio is not the same for all RPM (as he stated in argument #5, so if your gear transmission is correctly designed (as well as the car's aerodynamics), you should drive at the speed limit.
His math is often bad. At 3:32 he explains that V^3 (velocity cubed) means the power increases "exponentially", but he doesn't understand what this means. V^3 is a polynomial function (simply cubed). Exponential would be something like F^V (F to the power of V, where F is some factor, and V is velocity again). That grows much faster with increases in V, which is why "exponentially" means growing very fast. But this is not exponential. He repeats this "exponential" mistake later too. Maths may not lie, but people can lie about maths (though I don't think this was intentional).
1) Drive fast when you need to stop (1:01) 2) Drive slow when you need to go (2:32) 3) Engine braking (5:22) 4) Hills: Slow Up, Fast down (7:35) 5) Shift Early (9:22)
Spot on video. "Drive fast when you need to stop" is literally the optimum way to approach a red light, where "fast" means "keeping the minimum speed as high as possible". This is only perfectly achieved if you know exactly when the light will turn green. You would immediately brake down to and maintain a constant speed that would carry you to the intersection in the time it takes for the light to turn green. In reality, there is some uncertainty as to when the light will turn, and traffic behind you might get annoyed if you apply your brakes "prematurely". So use your best judgment in traffic, and if feasible, use engine braking exclusively to slow down as you approach the light, so that you are at least decelerating at a steady but modest rate well before the intersection, buying yourself more time to coast while not using any fuel, and not annoying the cars behind you to do so. "Drive slow when you need to go" is pretty accurate most of the time, except when the speed limit itself is set very low. If you can reasonably get away with driving over the speed limit when the speed limit is 5 mph, 10 mph, or 15 mph, you will get significantly better fuel economy in basically any vehicle (FE at 10 mph is approximately double the FE at 5 mph, and FE at 20 mph is typically somewhat close to double FE at 10 mph). Cars typically achieve their best fuel economy somewhere between 20-40 mph, with small-engined, low power/weight cars (ie Toyota Prius) peaking in the lower end of this range, and large-engined, high power/weight cars (ie Chevrolet Corvette) peaking in the upper end of the range. The drop in fuel economy due to increasing air drag is usually not significant until speeds reach 50+ mph, depending on the aerodynamics of the vehicle. For best highway fuel economy, drive in the far right lane as slow as you safely can. The denser traffic is, the smaller your speed differential relative to the flow of traffic needs to be. If traffic is very sparse, you might be able to drive at the posted minimum speed limit, but when doing so, you need to be constantly watching for cars approaching from behind in your lane and accelerate to a reasonable speed as they get close. Never drive slower than the posted minimum in clear and dry road conditions when traffic is freely flowing. You will notice the most dramatic improvements in fuel economy using this technique on the higher speed limit freeways. "Slow up; fast down" for hills is optimal because it reduces your vehicle's average speed and allows the engine to do its work in a more efficient manner. You might also find that hills where the elevation change is substantial enough, increasing throttle on the uphill sections such that your speed drops gradually to 5-10 mph below the speed limit by the crest of the hill, places the engine at a more favorable BSFC. Then coast down the hill in neutral or in highest gear with very light throttle to allow as much of the stored potential energy to be converted to kinetic energy as possible. "Shift early" is an optimal strategy because it keeps engine rpms down and engine load higher, which places the engine at a more favorable BSFC, as long as you're not lugging the engine. As far as accelerating softly; this is actually not as efficient as accelerating at higher engine load, depending on the distance between stops. In city driving and on residential streets, accelerating harder (half to three-quarters throttle) from a stop light/stop sign allows you to reach the speed limit earlier using less fuel and begin coasting sooner to the next stop. If you want to lower your average speed, just don't accelerate all the way to the speed limit (say 5 mph under). If the speed limit is 45 mph, then accelerate to 40 mph efficiently and quickly, hold at 40 until you're close enough to coast to the next stop, then coast in neutral the remaining distance. You can take this one step further and try pulse-and-glide, traffic permitting. You would accelerate to 45 quickly and efficiently, then immediately begin coasting in neutral, down to 35 or so, and then accelerate again quickly and efficiently back to 45, and repeat the process as necessary to cover the distance. This method of driving is a lot more fuel efficient than driving at a steady 40 mph, since the engine would be at a very low load driving at a steady 40 mph. Of course, driving a manual transmission vehicle gives you more control when applying these techniques.
I do that in traffic. People doesn’t understand that packing more vehicles into smaller and smaller spaces, until everyone stops, is why we all stop. If everyone coasted in traffic, we would go faster and faster.
@@johnsimun6533 none of them. A bunch of idiots on the road I tell you. My worst pet peeve are drivers who tail gate you cause they think if I speed up to the red light, the light will change faster. These are the same people who take forever to take off from a green light.
Almost correct. You should drive an automatic of the proper type. With a modern ECT or DCT you don't have the losses of a torque convertor and the computer is much better at keeping the engine in the optimal rev range than you are. Depending on the application a CVT or serial hybrid system can actually be the most efficient solution.
A lot of this advice is also a good way in extending the life of your braking system as well. Also, for the love of God, no slow up, fast down on freeways.
@@kunstderfugue only if traffic is light enough for people to easily get around you, cause if you are the one causing a train of cars behind you, I would like to slap some sense into you
@@kunstderfugue For long hills, you don't need to slow down because you can do that when you near the top of the hill. And since the aerodynamic drag doesn't change much, might as well stay at cruising speed for higher efficiency until you near the top of the hill since the load (weight of your car x distance x grade of hill) remains constant.
Pablo López-Ortega usually hills on highways are quite long so like others have said unless traffic is extremely light then no you’re going to cause problems.
Jeremy Clarkson said something about frequent braking wasting fuel a while back. Some cyclist got in the way and he joked about running them off the road to save fuel or something like that lol
I've actually been doing most of these since I started driving. I'm geeky. I like efficiency. I went and learned all this and literally made a lifestyle out of it. But as he said, at the same time I had to learn to be courteous and aware of what other people are doing around me. I highly recommend everyone do the same. You can only maximize a lot of these techniques on relatively empty roads. Coasting alone I find saves you the most. you can still coast and not bug ppl too much, just don't brake last minute.
Somehow mine freaks out and thinks I don't see the light since I'm slowing too gradually for her to tell I'm doing it on purpose. Conversely, I think she's not paying attention because she stop accelerating later and brakes harder.
I had to teach my boyfriend this recently, but he's quite logically minded and open to ideas so he was quite receptive to it. After a bit of practice he found that not only was the ride smoother from not having to brake as much, but overall range increased by ~15%. Unfortunately he still gets caught up in fear based ideas though.. like our Range Rover had DPF issues a number of months back so now on his way home from work if the DPF system starts a regen cycle he will purposely drive an extra 15-20km around the highway before coming home, wasting time and fuel just because he's scared it will immediately clog up on him if he doesn't. For reference, the issues it had were quoted by our original dealership to be $3,000 in repairs.. while another dealer literally at the other end of the street just updated the software in 45 mins for free which fixed all the errors and improved economy by 1/3rd instantly.
@@santiagodamelio1013 Some of this works in iRacing, but not everything. Mainly due to its far-from-perfect fuel consumption calculation ... iRacing only checks gas pedal position, it doesn't care about rpm. So coasting works, but using higher gear doesn't.
@@TheUchihasparky It's a joke relating to how Americans call unleaded fuel 'gas', while in the UK, Australia and some others we call it 'petrol'. Here in Aus, gas refers to LPG which is a totally different animal. Ethanol is an interesting one, because when tuned correctly you can get significantly more power out of an engine, but you're certainly right that you use more of it. In general, 100% ethanol means ~30% worse economy. As such, E10 (10% ethanol) is 3% worse economy. The reason why some encourage it though is that the emissions and production are better for the environment when compared to regular unleaded.. but depending on the area and production facility that is still being debated too.
@@MotoCat91 Yup, the fertiliser production and soil destruction of corn agriculture means ethanol often hits a higher total carbon footprint than just using petrol. Leave it for racecars and liquor stores imo
Great tips! In addition to those, when climbing a long hill you should speed up. Longer your engine works against gravity, more fuel burns. Don’t forget that gravity causes acceleration in the opposite direction when going uphill.
That actually isn't the case, for two reasons. 1) It takes the same amount of energy to go over a hill no matter how long it takes you to climb the hill. Potential energy= mass x height x acceleration due to gravity. However, 2) the faster you go, the more air resistance there is, meaning it will take more energy to climb the hill. In conclusion, driving uphill faster will take more gas than driving up the same hill at a slower speed. On another note, if the terrain is very hilly (up and down), it is beneficial to speed up slightly and not brake down a hill, because you will have more speed (kinetic energy) when you begin to climb the hill on the other side, meaning you will need to use less gas to climb the hill.
@Cloudchaser, you should go at least 4k rpms for more than 30 seconds once in a while. Not that you should do that every journey but once in a month would be enough.
@@martinwilliamson5250 i dont think so. I know your science checks out as far as the physics goes but you have to take into account the engine efficiency. Steadily speeding up a bit BEFORE a hill (which i think is what hes saying) helps you stay in low rpm high load when going the uphill part without significantly increasing air resistance relative to the overall engine power
Good video, good points covered. I was ready to say that in scenario #4, most likely the person behind you would be on your tail, flashing lights, and giving you the “you’re #1” sign. But you redeemed yourself with your final point to be aware of traffic around you. Well dome👍.
I think it's fair to mention that if the light turned green for the 45mph car it would have used up less fuel since it would have just continued at the same speed it was going. In my city there are a couple of roads where the green light turns on in waves and if you maintain a certain speed you will hit a green light on each intersection.
Here in the UK I have always tried to be economic. gentle acceleration and easing off the accelerator earlier when slowing, as in this video. I drive an Audi A4 S line diesel which is 16 years old. One thing I have found is that if I move my seat forward so that my foot is slightly more upright on the pedal, thus taking the pressure of just a little, it does in fact put the mpg up. My theory is that with the foot upright on the accelerator, near the instep and not the toe, any bump in the road (or just the normal tarmac unevenness) is evened out, thus putting less fuel into the engine. By having the foot more upright any slight jiggling is basically stopped. I told my older brother, and he now tells me that he finds the same, putting the mpg up by about 4-5 miles per gallon on a lengthy journey. Try it!
It became a huge misnomer, because everybody wants to sound smart, so they use exponentially for pretty much anything that can be defined as “more aggressive than linear”. They don’t even bother
hah! I was thinking the same! But I always feel that I'll come off as a dickhead every time I want to correct people on that. So mostly I don't, but sometimes I do. It's amazing how many people, even with a fairly sound base in mathematics do this mistake!
3:30 Nope! To increase exponentially with the velocity it would have to be something like 2^v, not v^3. So it increases "cubically" (if that's a word).
You're also putting more wear and tear on your engine when you're stopping and starting as opposed to coasting to the light. This also applies on takeoffs.
Slower speed doesn't always correlate to better fuel economy and neither does more load at low rpm. As cylinder pressure (load) increases, the air/fuel ratio gets richer to make more power and prevent knock. This is especially true with TGDI engines where low speed pre-ignition is a major concern. An air/fuel gauge can be very valuable in this case as you can keep the rpm down and throttle open to just before the ECU increases the short term fuel trims. For the speed, same deal. Too low of rpm at too low of speed can lug the engine which you don't want. I was shocked to find that my wife's Altima actually got better fuel economy at 55 mph than it did at 45 mph. That engine is just at a more efficient rpm and load at 55 mph, enough so to overcome the increase wind resistance. Another note to that also, wind resistance only starts to become a big factor above about 55 mph. Below that speed, the air can usually drift over and around the car pretty easily. Above that, it doesn't have time to move out of the way and air pressure begins to build in front of the car. This also increases the drag (vacuum) generated behind the car. That air dam in front is something we take full advantage of in racing.
in austria the light method even works well when the light is green. Here the green light will blink 4 times (4 seconds) before it will turn yellow (1 second) and then it will go to red. So you have 5 seconds to estimate if you will still be able to make it or not. If you dont, you just leave of the gas and use engine breaking :)
Only thing i gotta say is please don't be that person that slows down every time you go up a hill if you have a line of cars behind you. If you are by yourself, go for it.
Sometimes slow acceleration is bad because you will get more red stoplights in city driving instead of cruising through a greenwave. depends a bit on the system the traffic lights use. Some lights are out of sync when you apply the speed limit, that sucks
I just bought a 02 Ford Ranger 3.0L because my 03 Dodge Dakota 3.9L wasn’t cutting it on fuel mileage (averaging 15.6mpg under good driving practices) mostly due to it weighing 5500lbs and having a V6 with an outdated engine design and fairly wide tires (245mm). When I first got the Ford, I drove it semi-hard to get a feel for how it handled, and on that tank I averaged 17.5mpg, which was terrible given the rating was 17-21mpg, but still an improvement over the Dodge. However, following the next fill up, I used most of these techniques listed here and averaged 21.3mpg, which is higher than the max highway efficiency rating. I’m going the same distance every week on a single tank of gas while spending $10 less at every fill up. 🔥
i was able to save a lot of fuel using cruise control a lot. i don't know if it is the same for older systems as well but my VW G7 with DSG accelerates like you just describes (medium throttle very early shifting) and i get the main savings because the cruise control maintains the speed more constant(ly) than my foot would ever be able to. so the electronics are trying to use the least amount of fuel to maintain the speed. thats a win win i guess.
Old video but a great one. I've recently upgraded my car and now have dynamic cruise control that keeps me a set distance behind the car in front, I think I've got mine to 2 seconds gap. I'm amazed how close everyone else drives, causing them to stop start. Sooner self driving cars come in the better.
I always try to do this while driving and get drivers behind me flashing their high beams at me to speed up or using their horn to alert me.. I don’t understand people sometimes.. there’s a clear red light ahead, it’s not about who gets there the quickest
At around 3:15 you demonstrate that the power needed to drive depends upon velocity cubed (v^3), which is true. However, the power is the energy spent per unit time. As the time spent on road would be shorter at higher speed, the power is not directly related to fuel economy. A better approach would be to estimate the work done to go from point A to point B at a constant velocity, which is the energy used. Work is the force multiplied by the distance, which means that it depends upon velocity squared (v^2). It still means that driving faster gets you worse fuel economy, but driving 80 mph instead of 75 mph would spend 13.8 % more fuel for the same distance, and not 21.4 %.
From my experience living in Vermont. Very few people drive the speed limit, and this is especially true going up a hill and down a hill. Brakes are rarely used, except when stopping/turning, the car in front of you braking or turning and tail gaters lol.
Engine braking is best used when you think about the distance between yourself and other cars. It’s hard to do if you’re riding someone’s tail but if you keep the 3 second rule you can definitely pull it off. The only time I brake on the highway is the tight exits that are significantly reduced speeds because of the curves.
i just try to time the traffic lights so i never have to come to a complete stop, it doesn't always work but i think if you do this, you'll always get the best gas milege possible. i'm getting around 38-41 mpg in my 2012 Chevy Sonic doing this.
8:00 tip #4 thats why I sometimes prefer not to use cruise control as it tries to maintain speed regardless of elevation, while I rather accelerate downhill and slow down uphill
Eco mode in VWs actually disengages the clutch and keeps the engine in idle - so burning a tiny bit of fuel but no engine braking (unless in S mode) - this is great for low MPG coasting as it allows you to coast for long stretches (like changing altitude), but not useful for engine braking.
Fun fact if you own a vehicle in the VW Audi group and your car displays the gear you’re in; if you’re driving in Efficiency mode and let off the gas, it will disengage the transmission and go in to a “coast” mode. You’ll know when it is doing it because instead of seeing an “E5” showing the mode and gear selected, it will just show “E “. Alternatively if you want to go into “coast” at anytime, just let off the gas and; if it is safe to do so, tap the + paddle if you have one. This also puts the car in the “coast” mode until you input either brake or throttle; at which point the car already has the gear ready for you. Pretty clever really. On my work commutes when I don’t feel like burning money unnecessarily, I cruise at 55 and use the coast mode a lot. One day I managed to get my A4 SLine up to 66MPG. And then on the weekend, it’s back to 19MPG 😉 Not sure if any other manufacturers have this, would be interested to know 👍🏼
Best way to sum it all up is: keep your feet off your brake pedal AND your gas pedal except when absolutely necessary. You convert energy of momentum to heat when you press the brake pedal and you use gas anytime you press the gas pedal. Obviously you have to press the gas pedal to get anywhere, but anytime you can avoid pressing the gas you should and anytime you can avoid pressing the brake you avoid converting movement to heat.
Love this channel. It had taught me a lot of engineering concepts and inspired me to start my own UA-cam channel. I would love some feedback and support.
Triple like this one. I always wanted to find an efficient way to communicate exactly this to people. Now, I can just reference it. I call it a "red light race" as drivers are competing, who will be at the red light first and sitting there with engine idling. Similar to the hill racing. This, btw, shows that using cruise control is not the most efficient way of driving. Thank you very much for this video! Love it!
I have another "technique" for myself: don't talk to your passengers while accelerating. I notice that I can basically pay full attention to 2 things at a time while accelerating, and those are ideally proper control of the car and the traffic around you. When I talk to someone next to me, I find I still pay full attention to the traffic around me and to the conversation. This results in shifting from 2nd to 3rd at around 40 km/h instead of 30, and 3rd to 4th at around 45 km/h instead of 35. Fortunately it's still safer than not paying attention to the road, but it does cost fuel.
I would love to see an explanation involving using cruise control at lower speeds in the city between lights and also how to get the best fuel efficiency when driving a manual transmission because they are still out there
Is it? I haven't driven in Germany but I've driven in Italy and Austria around ski resorts where there are quite a lot of German drivers as well and I was left with the impression that they don't really think about driving efficiently. They were constantly just going fast and then slamming on the brakes when they needed to slow down. I guess when you drive a 100k$ Audi which can stop well even on wet roads you just forget how important the way you drive actually is.
@@peterm3861 In Finland they teach it in theory and in practice. And also they show how much your consumption dropped after focusing on economic driving.
I watch drivers and can come to no other conclusion that folks just don’t care about fuel efficiency. Jack rabbit starts and then pour it on until shut it down wearing brakes, straining transmissions and PVC systems. I don’t drive like an old man, but am proud that my 2012 Acadia with 162,000 miles still has original pads and rotors.
My GLA45 actually has a coasting (Merc badge it “glide”) mode. It’s very effective and cleverly designed. But as a fuel consumption reduction aid the engine is so wonderfully powerful you can’t really tell the specific results at the pumps. Sadly I spent all my time typing this and then turning the sound down as my wife’s says “what rubbish are you watching now?” So I have to re-watch the whole session. Now was that very efficient......
I think there is an error in Velocity cubed. Should be simply velocity squared from drag formula as we do not mix velocity measured against relative wind and car velocity measured against ground. Aerodynamic drag formula is against relative wind and it is simply velocity squared. May vary due to headwind/tailwind but not due to groundspeed.
The hill scenario is where I will always defend a high torque/long stroke motor. So much easier to keep revs down low when climbing a hill vs a short stroke engine that makes it's power on higher RPMs.
During your engine braking example, you indicate that the car uses no fuel until the car is idling at the stop light, but my car continues to idle while coasting towards the stop light and idling uses fuel. Additionally, my Charger, with its 8 speed transmission, likes to downshift as it is coasting. Each downshift raises engine RPMs and I would think that would increase fuel use.
I just got done smoking some delicious zkittles from Alien Labs rolled in a swisher sweet. I kept it simple today, it’s the little things. Anyways the equation you have on the board is a simple one of course but nevertheless, in my 26 years of life I haven’t really cared of enough to try and understand these type of equations but today, a cold dry morning, I understood the equation. Very well put sir.
Highway cruising, every vehicle has a "sweet spot", the RPM in high gear where the engine is the most fuel efficient. In my vehicle that's at 2100 RPM which is 78 MPH or so. I used to drive thousands of miles a year on long highway trips. I set the cruise control at different speeds and checked my mileage. Slowing down to 70 MPH from 80 MPH cost me about 10% in milage.
So, vehicle speed was the only factor that contributed to this increase? Fuel quality, ethanol content, wind direction, tire inflation, tire brand, elevation changes, cargo/load, A/C, alignment, engine tune...you controlled for all of these and still had a reduction in fuel economy despite what every study has ever shown? That's weird.
I do most of this, get an average of 52 mpg in an 2018 Elantra mix of around 40% city and 60% highway driving, record was 61.8 mpg on a tank but that was 90% highway driving.
Disregard my last comment for the fact that I just scrolled down and saw you had posted a video already regarding manual transmission and shifting for fuel economy LOL
I use the eco mode indicator in my corolla to govern my acceleration. I only go to the top of the eco if I have to merge or make a turn. Overall, most people are just flying around in a constant race and not even thinking. It’s no way to live, although I was one of those people for decades.
How to do engine braking? 1) gears should be in engage position or gears should be in Neutral position 2) if gears are engaged then whether I have press clutch pedal or not?
I try to time traffic lights to where I never have to stop... When possible and not being rude to other drivers. VW has great info you can watch to achieve better mileage. One is watching instant mpg. Many times coasting in 5th gear (in a manual) is better than coasting in 6th because the computer will shut off fuel in 5th and not 6th.
Ive been doing all of this already. Just by logic alone. Weird. I don't think about it or know the mechanics, i just felt it was right and i generally follow my gut.
I have done these techniques for years. Never knew why i got great gas mileage. Everyone always wondered why i could get 42 to 45 mpg out of a 2010 Hyundai Accent. If im not mistaken it was only supposed to get 36mpg on the highway. 🤔
In other words just remember people get mad if you go 2 mph under the speed limit. Or take too long getting to a red light just so you all can wait at it. People are really just something special.
3:30 Point of order, it's polynomial (more specifically cubic) increase, *not* exponential increase. Exponential would be if the velocity was in the power, like say 3^v.
awesome,. helps me as a beginer!!! and i always do that, especialy on stops, when i see its red or i go near like 100m like i let gas pedal and when i feel it req i brake slowly trough the first car i see
A few years back when I worked MC dispatch I used to do a semi regular run from London to Leeds - a run of roughly 200 miles My bike - if ridden conservatively in a straight line - i.e a nice leisurely 65mph on the motorway - had a range of just over 200 miles. At 80mph the range dropped to about 160 miles. So If I decided to race up to Leeds, it meant I couldn't make it on a single tank and I'd have to stop on the motorway where fuel was considerably more expensive and which also meant I didn't have enough fuel for the return journey without a second fuel stop. So I could drive faster, give myself more stress, make more stops, and spend more money - or drive slower spend less money make less stops and have less stress - and still do the round trip in more or less the same time. Driving faster is not a substitute for good journey planning
"The amount of power that you need to produce increases exponentially as your speed increases because the aerodynamic power required is a function of velocity cubed". I think you meant "rapidly" there instead of "exponentially". Last time I checked, exponential was exponentially more rapid than cubed.
On the hill scenario. There are variables missing from that analysis. Time, distance, and fuel consumption rate. Assuming fuel consumption is the dependent value speed, time, and distance would be i independent values. The absolute value for each standardized coefficient of the independent variable will sign the variance each coefficient has on the dependent variable. This will give an accurate answer to the questions. Maintain speed up the hill or decelerate as you go up the hill to reduce rate of consumption. N E how, I’m no expert but I thought I would give some input for consideration. If I was rally racing or mapping my route I would compute this for the terrain I will travel to maximize my fuel consumption. 😊
Not sure if anyone has stated this too, but also should be keeping in mind the amount of stops one would make for gas only. Let's say you have a 400 mile range at 65mph, but at 75 one only has 330 mile range per say. Now take in you are doing a road trip of 375 miles. That equates to one fill up you'd have to make if going 75, which is now a loss in time. You might end up evening out your time gained with your time lost in filling up. So it's just a waste in money.
Engineering Explained how do we identify whether the given car have turbo charger or not both from bonnet and as well as when driving. Please make a video on that bro
I love it when people fly by me while I'm coasting, have to stop, and then they have to watch me fly by them because the light turned before I got to it.
They usually end up a whopping 1 car ahead most of the time. All that throttle to save them 3 seconds off their journey.
Thats an amazing feeling.
@Tony, very true. Always have to check the cross traffic before breaking the coast. Another hazard is that someone towards the back of the line will get the urge to cut me off so they can beat the first car at the light.
Jase, I coast to a red light also when possible so you dont always have to stop but more often then not some idiot(s) will race past and cut back in front of you then stop at the red light, then you have to stop too as they seem to have a slow reaction to the green , maybe checking their phone while stopped?
I drive like you too and I make a game as to when I'll see a car that flies past me at which light and how often.
@@roughas100 Yeah, that's what usually happens sadly.
I’ll go on record and say 95%+ of people don’t understand the concept of coasting
Haha nope, flying up to stoplights like it's gonna get them somewhere faster.
Engineering Explained right?! Or on the freeway with brake lights ahead and immediately on their brakes. Just coast... who knows, maybe you’ll never have to touch your brakes.. Save $ on both brakes & gas...
x-hook Tow Hook i thought it was common sense🤷♀️
JordaniusVonRhod it’s quite the opposite. Most ppl only know 2 things - stop & go
@@x-hooktowhook3904 or they know but don't care if they get good mpg I totally understand hell if I could go everywhere fast I would too
It really amazes me how big a hurry so many people are in to wait at a red light.
Gotta respond to that new notification on their phone!
The reason realy is, atleast here in Germany, that the traffic lights have weight sensors.
So if there is no car standing at the white line, the light will stay red for longer
They're trying to get in front of you whose driving under the speed limit.
I'm so glad to see I'm not alone. Also, when in heavy traffic, I refuse to start and stop 50 times. I'd rather coast at 15km/h in first gear.
I see that everyday I going to work. Even I pass them at every green, them race ahead - never learn!
"Use common sense while driving"
Yeah, good luck with that statement.
I can’t do it due to paranoia it’s so stressful for me to drive…
@@oliviadart612 drinking is a good fix
I save money on gas by buying a new car everytime I run out of gas.
lol, saving on 'gas' but not 'money'
I really hope your local dealer fills the tank before the purchase ... :)
Bruh what? 😂💀
I didn't think I'd have to make it obvious that this is a shitty joke.
@Stephen Hill r/woosh
Friends and family make fun of my 'old man' driving because I use these techniques whenever I can but are surprised that I maintain my speed limit on-ramps instead of braking like everyone else. They're even more surprised when my driving gets spirited in curves. Little do they know that I'm keeping myself entertained by challenging myself to drive efficiently.
What is about highway ramps that cause people to brake even when it's completely unnecessary? I see this every single day, and it drives me nuts.
@@rars0n people just have no confidence driving,
@@rars0n
I concur strongly;
Adam Baldwin most exit ramps you gotta brake unless you wanna go flying into traffic
@@dylanroselle6130 the ramps not the exits, where you should be increasing speed from 40mph to 80mph
I have never seen in my limited 5 years of driving experience ever seen anyone else coast in traffic like i do. Helps alleviate traffic and saves money and makes you calmer and more focused driver.
Yes, after 35 years of driving, 10 years bicycle commuting, and now a couple of years on a motorcycle commuting, I'm really not in a rush to go anywhere. If people are getting all uptight I'm VERY happy to move over and let them get as far away from me as possible. If someone wants to drive like a nut, there you go buddy you just move on past and get in front of me. WAAAY in front. Enough that I have time to brake before I come to the wreck you caused.
Exactly. Especially merging. I'll go off on a whole rant there if I get started. Idk why people think 6 inches off anothers bumper is the fastest way to move.
@John. Agreed. I had to drive cross country a lot due to a job. Out of boredom, I'd play with the math to see what different speeds would save me time wise. Not worth it usually.
A trick I like is someone hanging in your "blind spot" ( i have too many mirrors to have one) when you want to lane change. Blinker makes them be nice and slow down or be an ass and punch it. Either way, they are now out of your blind.
@@paulparoma rushing, pride, and a false sense of invincibility. That's what I think are the main culprits to the frantic, unsafe, racing mindset many drivers have...
@@paulparoma agree. Advertising gone wrong, perhaps. Nobody can defy physics, even if we all want to...!
It's almost impossible to coast with a 45-50 mph speed limit at red lights. They change to red to fast which makes roundabouts actually safer.
Last time I told my friend to Coast, he went to the beach.
As long as you're at Daytona, no harm, no foul.
Syphoning gas from other cars is a great way to save money at the pump ⛽
It may cost the car owner a bullet...
Sharing is caring, right?
@@stevelovesgod That's kinda psycho
@@Larcona_
Yeah, you'd be crazy to try and syphon fuel out of a person's vehicle... you may just get shot
@@stevelovesgod Yeah, my point is that shooting someone for syohoning gas is psycho
Most satisfying thing is when one of those drivers that thinks he is cool overtakes you and eventually he just ends up standing still at a stop and you just cruise pass him.
The best Hack is to just not go anywhere because the outside world is dangerous
Stay inside. Mac n' Cheese. There there. Everything's going to be okay. 😂
You don't have to pay for fuel if you aren't using any.
smittywoodshop so true your chances of dying are higher when you leave your house lmao
This reminded me soo much of YOLO by Lonely Island from when it first came out
That did not age well...
I learned that first method with stop lights while driving motor scooters in town. If you slow down to give yourself more time before reaching the red light you have a better chance of reaching it still moving and you actually end up passing everyone that had rushed up to the light and then stopped.
I have been especially interested in vehicle efficiency for about a decade and I can stand behind all your explanations. Even though I knew most of these I'm glad to hear it explained so clearly and with great detail.
I have a manual car and I think it was your channel that taught me to engine brake to save fuel. 👍
same here. But sometimes my rev matching is not that perfect(especially 3rd to 2nd), but im still learning
@@Yathuprem you have to understand how to double clutch . Look videos about it
Love your MPP profile pic
I have a sonic turbo manual and it doesn't shut off fuel unless above 3k rpm... Thanks chevy engineers.
@@TheCorecovers i mean you could do that but that's not really going to do much except make your synchros last longer. would be smoother, yes, but if you have synchros in your car then you should just use them. normal downshifting will be quicker and more practical in normal traffic.
Don't drive like a teenager that stole his Dad's sports car. Got it!
You mean, don't drive like Nikki Catsouras.
Occasionally you've got to drive it like you stole it (or rented it).
@@Unchained_Alice Grandma has a lot of experience, after all!
Don't drive at all ;)
Or your mom's minivan
Don't know why but minivans are a lot of fun when driving fast
i love how Jason supported everything with mathematics ang computation. no beliefs and speculations. maths dont lie.
It gets addictive over time
Yeah but he still makes mistakes.
The power used to fight fluid friction is indeed dependent on v², but the coefficient C_d (d for drag) is ALSO dependent on speed. Sometimes, you can increase your speed by just a little bit, and C_d gets divided by 2, which is nice.
Also the power produced by the engine is not exactly the same as fuel consumption, because the efficiency ratio is not the same for all RPM (as he stated in argument #5, so if your gear transmission is correctly designed (as well as the car's aerodynamics), you should drive at the speed limit.
His math is often bad. At 3:32 he explains that V^3 (velocity cubed) means the power increases "exponentially", but he doesn't understand what this means. V^3 is a polynomial function (simply cubed). Exponential would be something like F^V (F to the power of V, where F is some factor, and V is velocity again). That grows much faster with increases in V, which is why "exponentially" means growing very fast. But this is not exponential. He repeats this "exponential" mistake later too. Maths may not lie, but people can lie about maths (though I don't think this was intentional).
@@johnjones7400 yeah, I was like... That's not exponential, lol
1) Drive fast when you need to stop (1:01)
2) Drive slow when you need to go (2:32)
3) Engine braking (5:22)
4) Hills: Slow Up, Fast down (7:35)
5) Shift Early (9:22)
6) Don't annoy others while doing these (11:43)
thank you r p
Don't drive fast to stop is retarded
@@vanandgasparyan1430 ir they all do that apart of saving tons of fuel they wouldn't be annoyed u.u
Spot on video.
"Drive fast when you need to stop" is literally the optimum way to approach a red light, where "fast" means "keeping the minimum speed as high as possible". This is only perfectly achieved if you know exactly when the light will turn green. You would immediately brake down to and maintain a constant speed that would carry you to the intersection in the time it takes for the light to turn green. In reality, there is some uncertainty as to when the light will turn, and traffic behind you might get annoyed if you apply your brakes "prematurely". So use your best judgment in traffic, and if feasible, use engine braking exclusively to slow down as you approach the light, so that you are at least decelerating at a steady but modest rate well before the intersection, buying yourself more time to coast while not using any fuel, and not annoying the cars behind you to do so.
"Drive slow when you need to go" is pretty accurate most of the time, except when the speed limit itself is set very low. If you can reasonably get away with driving over the speed limit when the speed limit is 5 mph, 10 mph, or 15 mph, you will get significantly better fuel economy in basically any vehicle (FE at 10 mph is approximately double the FE at 5 mph, and FE at 20 mph is typically somewhat close to double FE at 10 mph). Cars typically achieve their best fuel economy somewhere between 20-40 mph, with small-engined, low power/weight cars (ie Toyota Prius) peaking in the lower end of this range, and large-engined, high power/weight cars (ie Chevrolet Corvette) peaking in the upper end of the range. The drop in fuel economy due to increasing air drag is usually not significant until speeds reach 50+ mph, depending on the aerodynamics of the vehicle. For best highway fuel economy, drive in the far right lane as slow as you safely can. The denser traffic is, the smaller your speed differential relative to the flow of traffic needs to be. If traffic is very sparse, you might be able to drive at the posted minimum speed limit, but when doing so, you need to be constantly watching for cars approaching from behind in your lane and accelerate to a reasonable speed as they get close. Never drive slower than the posted minimum in clear and dry road conditions when traffic is freely flowing. You will notice the most dramatic improvements in fuel economy using this technique on the higher speed limit freeways.
"Slow up; fast down" for hills is optimal because it reduces your vehicle's average speed and allows the engine to do its work in a more efficient manner. You might also find that hills where the elevation change is substantial enough, increasing throttle on the uphill sections such that your speed drops gradually to 5-10 mph below the speed limit by the crest of the hill, places the engine at a more favorable BSFC. Then coast down the hill in neutral or in highest gear with very light throttle to allow as much of the stored potential energy to be converted to kinetic energy as possible.
"Shift early" is an optimal strategy because it keeps engine rpms down and engine load higher, which places the engine at a more favorable BSFC, as long as you're not lugging the engine. As far as accelerating softly; this is actually not as efficient as accelerating at higher engine load, depending on the distance between stops. In city driving and on residential streets, accelerating harder (half to three-quarters throttle) from a stop light/stop sign allows you to reach the speed limit earlier using less fuel and begin coasting sooner to the next stop. If you want to lower your average speed, just don't accelerate all the way to the speed limit (say 5 mph under). If the speed limit is 45 mph, then accelerate to 40 mph efficiently and quickly, hold at 40 until you're close enough to coast to the next stop, then coast in neutral the remaining distance. You can take this one step further and try pulse-and-glide, traffic permitting. You would accelerate to 45 quickly and efficiently, then immediately begin coasting in neutral, down to 35 or so, and then accelerate again quickly and efficiently back to 45, and repeat the process as necessary to cover the distance. This method of driving is a lot more fuel efficient than driving at a steady 40 mph, since the engine would be at a very low load driving at a steady 40 mph.
Of course, driving a manual transmission vehicle gives you more control when applying these techniques.
How to Drive Efficiently: Have a Ford Raptor tow your car wherever you're going
But who pays for the fuel for that 2.5-ton truck?
@@vincentxu8217 the Tesla owner
Have a Big Truck, tow your Ford Raptor and go everywhere.
@@vincentxu8217 México will pay for it
@@AH-lw2bj you can't tow Tesla's easily
In a nutshell : Drive as a truck driver
Yes I once read truckers call it "inertia driving".
I do that in traffic. People doesn’t understand that packing more vehicles into smaller and smaller spaces, until everyone stops, is why we all stop. If everyone coasted in traffic, we would go faster and faster.
So, murder prostitutes?
@@johnsimun6533 none of them. A bunch of idiots on the road I tell you. My worst pet peeve are drivers who tail gate you cause they think if I speed up to the red light, the light will change faster. These are the same people who take forever to take off from a green light.
@@godsinbox leave the working women alone! Let them work, let them live.
1. drive a manual.
2. keep the revs low.
3. quit mashing the throttle at every light.
I get better combined mpg than the internet says i should be getting on the freeway. Anyone else?
Absolutely
Basically.
drives an STI
i want to hear the turbo whistle loool
Almost correct. You should drive an automatic of the proper type. With a modern ECT or DCT you don't have the losses of a torque convertor and the computer is much better at keeping the engine in the optimal rev range than you are. Depending on the application a CVT or serial hybrid system can actually be the most efficient solution.
A lot of this advice is also a good way in extending the life of your braking system as well.
Also, for the love of God, no slow up, fast down on freeways.
If you can go to the slow lane I'd say it's alright
@@kunstderfugue only if traffic is light enough for people to easily get around you, cause if you are the one causing a train of cars behind you, I would like to slap some sense into you
also your engine and transmission will wear less
@@kunstderfugue For long hills, you don't need to slow down because you can do that when you near the top of the hill. And since the aerodynamic drag doesn't change much, might as well stay at cruising speed for higher efficiency until you near the top of the hill since the load (weight of your car x distance x grade of hill) remains constant.
Pablo López-Ortega usually hills on highways are quite long so like others have said unless traffic is extremely light then no you’re going to cause problems.
Jeremy Clarkson said something about frequent braking wasting fuel a while back. Some cyclist got in the way and he joked about running them off the road to save fuel or something like that lol
I've actually been doing most of these since I started driving. I'm geeky. I like efficiency. I went and learned all this and literally made a lifestyle out of it.
But as he said, at the same time I had to learn to be courteous and aware of what other people are doing around me. I highly recommend everyone do the same. You can only maximize a lot of these techniques on relatively empty roads.
Coasting alone I find saves you the most. you can still coast and not bug ppl too much, just don't brake last minute.
gonna have to make my wife watch this so she can finally understand why i drive the way i drive...
If wives would listen, no men would want a divorce.
Somehow mine freaks out and thinks I don't see the light since I'm slowing too gradually for her to tell I'm doing it on purpose. Conversely, I think she's not paying attention because she stop accelerating later and brakes harder.
good luck with that
I had to teach my boyfriend this recently, but he's quite logically minded and open to ideas so he was quite receptive to it.
After a bit of practice he found that not only was the ride smoother from not having to brake as much, but overall range increased by ~15%.
Unfortunately he still gets caught up in fear based ideas though.. like our Range Rover had DPF issues a number of months back so now on his way home from work if the DPF system starts a regen cycle he will purposely drive an extra 15-20km around the highway before coming home, wasting time and fuel just because he's scared it will immediately clog up on him if he doesn't.
For reference, the issues it had were quoted by our original dealership to be $3,000 in repairs.. while another dealer literally at the other end of the street just updated the software in 45 mins for free which fixed all the errors and improved economy by 1/3rd instantly.
Trade in your wife for two 20 year ago girlfriends.
Coming from sim racing I've been using these techniques and manage time to take less pit stop.
Works well.
IRacing?
@@santiagodamelio1013 i mainly play project cars 2, and dirt rally 2.0 This technique works in GT Sport too.
@@santiagodamelio1013 Some of this works in iRacing, but not everything. Mainly due to its far-from-perfect fuel consumption calculation ... iRacing only checks gas pedal position, it doesn't care about rpm. So coasting works, but using higher gear doesn't.
@@kenkalajdzic ah that's interesting, I never played Iracing because of the monthly fee. I already have a mmorpg for that..
I live in the uk, and we save money on gas by buying petrol
Gas is petrol. Did you mean E85? (Ethanol) if you did mean E85, you will actually use significantly more fuel then if you used petrol.
@@TheUchihasparky It's a joke relating to how Americans call unleaded fuel 'gas', while in the UK, Australia and some others we call it 'petrol'.
Here in Aus, gas refers to LPG which is a totally different animal.
Ethanol is an interesting one, because when tuned correctly you can get significantly more power out of an engine, but you're certainly right that you use more of it.
In general, 100% ethanol means ~30% worse economy. As such, E10 (10% ethanol) is 3% worse economy.
The reason why some encourage it though is that the emissions and production are better for the environment when compared to regular unleaded.. but depending on the area and production facility that is still being debated too.
@@MotoCat91 yes, we essentially grow ethanol. And yes you get more power and its higher octane then 93 octane, but like I said, you use more of it
MotoCat leave it bruhh.. this fella is all gassed up. He’s not gonna get it
@@MotoCat91 Yup, the fertiliser production and soil destruction of corn agriculture means ethanol often hits a higher total carbon footprint than just using petrol. Leave it for racecars and liquor stores imo
Great tips!
In addition to those, when climbing a long hill you should speed up. Longer your engine works against gravity, more fuel burns. Don’t forget that gravity causes acceleration in the opposite direction when going uphill.
That actually isn't the case, for two reasons. 1) It takes the same amount of energy to go over a hill no matter how long it takes you to climb the hill. Potential energy= mass x height x acceleration due to gravity.
However, 2) the faster you go, the more air resistance there is, meaning it will take more energy to climb the hill. In conclusion, driving uphill faster will take more gas than driving up the same hill at a slower speed.
On another note, if the terrain is very hilly (up and down), it is beneficial to speed up slightly and not brake down a hill, because you will have more speed (kinetic energy) when you begin to climb the hill on the other side, meaning you will need to use less gas to climb the hill.
i drive at 40km/hr with my rpm at 1000, automatic transmission rav 4. would that harm the car?
@Cloudchaser, you should go at least 4k rpms for more than 30 seconds once in a while. Not that you should do that every journey but once in a month would be enough.
@@martinwilliamson5250 i dont think so. I know your science checks out as far as the physics goes but you have to take into account the engine efficiency. Steadily speeding up a bit BEFORE a hill (which i think is what hes saying) helps you stay in low rpm high load when going the uphill part without significantly increasing air resistance relative to the overall engine power
"I sold my car... FOR GAS MONEY!!"
-Goku
0:51 look at that the cyber truck
Good video, good points covered. I was ready to say that in scenario #4, most likely the person behind you would be on your tail, flashing lights, and giving you the “you’re #1” sign. But you redeemed yourself with your final point to be aware of traffic around you. Well dome👍.
I think it's fair to mention that if the light turned green for the 45mph car it would have used up less fuel since it would have just continued at the same speed it was going. In my city there are a couple of roads where the green light turns on in waves and if you maintain a certain speed you will hit a green light on each intersection.
Here in the UK I have always tried to be economic. gentle acceleration and easing off the accelerator earlier when slowing, as in this video. I drive an Audi A4 S line diesel which is 16 years old.
One thing I have found is that if I move my seat forward so that my foot is slightly more upright on the pedal, thus taking the pressure of just a little, it does in fact put the mpg up. My theory is that with the foot upright on the accelerator, near the instep and not the toe, any bump in the road (or just the normal tarmac unevenness) is evened out, thus putting less fuel into the engine. By having the foot more upright any slight jiggling is basically stopped. I told my older brother, and he now tells me that he finds the same, putting the mpg up by about 4-5 miles per gallon on a lengthy journey. Try it!
"Power increases exponentially with speed" No, man! You just wrote that it increases polynomially! Exponentially would be P ~ exp(v)
Nice
Most descriptiona of exponential increase actually refer to polynomial indices, unfortunately. This is obviously a misnomer but it exists nonetheless.
It became a huge misnomer, because everybody wants to sound smart, so they use exponentially for pretty much anything that can be defined as “more aggressive than linear”. They don’t even bother
hah! I was thinking the same! But I always feel that I'll come off as a dickhead every time I want to correct people on that. So mostly I don't, but sometimes I do. It's amazing how many people, even with a fairly sound base in mathematics do this mistake!
@@mattegeniet very true, but I did not expect it from Jason!
I take great pride in timing out coasting to a red light and hitting it just as it turns green so I don't actually have to stop it's quite satisfying
TL;DW: To save fuel, go slowly and stay off the brakes. Imagine you have crates of tofu in the trunk... Oh wait
*Eurobeat intensifies.
Dashy902 *headlights appear in the distance behind you*
And an open cup of water in your cup holder!
*DEJA VU*
Flashback to Takumi's dad giving driving tips...
3:30 Nope! To increase exponentially with the velocity it would have to be something like 2^v, not v^3. So it increases "cubically" (if that's a word).
The 3 in a cubing function is called an exponent, fyi
You're also putting more wear and tear on your engine when you're stopping and starting as opposed to coasting to the light. This also applies on takeoffs.
Slower speed doesn't always correlate to better fuel economy and neither does more load at low rpm. As cylinder pressure (load) increases, the air/fuel ratio gets richer to make more power and prevent knock. This is especially true with TGDI engines where low speed pre-ignition is a major concern. An air/fuel gauge can be very valuable in this case as you can keep the rpm down and throttle open to just before the ECU increases the short term fuel trims. For the speed, same deal. Too low of rpm at too low of speed can lug the engine which you don't want. I was shocked to find that my wife's Altima actually got better fuel economy at 55 mph than it did at 45 mph. That engine is just at a more efficient rpm and load at 55 mph, enough so to overcome the increase wind resistance. Another note to that also, wind resistance only starts to become a big factor above about 55 mph. Below that speed, the air can usually drift over and around the car pretty easily. Above that, it doesn't have time to move out of the way and air pressure begins to build in front of the car. This also increases the drag (vacuum) generated behind the car. That air dam in front is something we take full advantage of in racing.
in austria the light method even works well when the light is green. Here the green light will blink 4 times (4 seconds) before it will turn yellow (1 second) and then it will go to red.
So you have 5 seconds to estimate if you will still be able to make it or not. If you dont, you just leave of the gas and use engine breaking :)
Only thing i gotta say is please don't be that person that slows down every time you go up a hill if you have a line of cars behind you. If you are by yourself, go for it.
Sometimes slow acceleration is bad because you will get more red stoplights in city driving instead of cruising through a greenwave. depends a bit on the system the traffic lights use. Some lights are out of sync when you apply the speed limit, that sucks
I do the stoplight trick all the time! Physics changed me for the better. I'm always thinking about the kinetic energy of my car.
I just bought a 02 Ford Ranger 3.0L because my 03 Dodge Dakota 3.9L wasn’t cutting it on fuel mileage (averaging 15.6mpg under good driving practices) mostly due to it weighing 5500lbs and having a V6 with an outdated engine design and fairly wide tires (245mm). When I first got the Ford, I drove it semi-hard to get a feel for how it handled, and on that tank I averaged 17.5mpg, which was terrible given the rating was 17-21mpg, but still an improvement over the Dodge. However, following the next fill up, I used most of these techniques listed here and averaged 21.3mpg, which is higher than the max highway efficiency rating. I’m going the same distance every week on a single tank of gas while spending $10 less at every fill up. 🔥
I really like my hybrid for engine braking that generates electricity
Sick
whenever i drive up to a stop light i see it as a failure in my route planning.
i was able to save a lot of fuel using cruise control a lot. i don't know if it is the same for older systems as well but my VW G7 with DSG accelerates like you just describes (medium throttle very early shifting) and i get the main savings because the cruise control maintains the speed more constant(ly) than my foot would ever be able to. so the electronics are trying to use the least amount of fuel to maintain the speed. thats a win win i guess.
I like that you can read "omph" in the first example, for most of the time that's the feeling breaking hard...
Old video but a great one. I've recently upgraded my car and now have dynamic cruise control that keeps me a set distance behind the car in front, I think I've got mine to 2 seconds gap. I'm amazed how close everyone else drives, causing them to stop start. Sooner self driving cars come in the better.
I always try to do this while driving and get drivers behind me flashing their high beams at me to speed up or using their horn to alert me.. I don’t understand people sometimes.. there’s a clear red light ahead, it’s not about who gets there the quickest
At around 3:15 you demonstrate that the power needed to drive depends upon velocity cubed (v^3), which is true. However, the power is the energy spent per unit time. As the time spent on road would be shorter at higher speed, the power is not directly related to fuel economy.
A better approach would be to estimate the work done to go from point A to point B at a constant velocity, which is the energy used. Work is the force multiplied by the distance, which means that it depends upon velocity squared (v^2). It still means that driving faster gets you worse fuel economy, but driving 80 mph instead of 75 mph would spend 13.8 % more fuel for the same distance, and not 21.4 %.
"Use common sense out there driving."
Common sense isn't so common anymore, especially with increasing drivers on cell phones. :
From my experience living in Vermont. Very few people drive the speed limit, and this is especially true going up a hill and down a hill. Brakes are rarely used, except when stopping/turning, the car in front of you braking or turning and tail gaters lol.
Engine braking is best used when you think about the distance between yourself and other cars. It’s hard to do if you’re riding someone’s tail but if you keep the 3 second rule you can definitely pull it off. The only time I brake on the highway is the tight exits that are significantly reduced speeds because of the curves.
#4: Also known as (best said with a hillbilly accent) "The Rolls-Canardly Driving Method. Rolls down one hill and Can'ardly make it up the next".
LOL
I had a LWB FJ55 landcruiser like that.... the good old days.....
i just try to time the traffic lights so i never have to come to a complete stop, it doesn't always work but i think if you do this, you'll always get the best gas milege possible. i'm getting around 38-41 mpg in my 2012 Chevy Sonic doing this.
It depends where you live as well. In Houston, people will honk at you even for going slightly below speed limit.
Me:FLOOR IT?!?!
Engineering: NO NO DON’T FLOOR IT!!
Me: OK FLOORING IT!!
*press gas pedal all the way down*
Only some would get this reference
8:00 tip #4 thats why I sometimes prefer not to use cruise control as it tries to maintain speed regardless of elevation, while I rather accelerate downhill and slow down uphill
Engineering Explained: *buys a Tesla*
Engineering Explained: Here's how you can save money on gas.
Eco mode in VWs actually disengages the clutch and keeps the engine in idle - so burning a tiny bit of fuel but no engine braking (unless in S mode) - this is great for low MPG coasting as it allows you to coast for long stretches (like changing altitude), but not useful for engine braking.
3:31 not exponentially, but cubicly :)
Fun fact if you own a vehicle in the VW Audi group and your car displays the gear you’re in; if you’re driving in Efficiency mode and let off the gas, it will disengage the transmission and go in to a “coast” mode. You’ll know when it is doing it because instead of seeing an “E5” showing the mode and gear selected, it will just show “E “.
Alternatively if you want to go into “coast” at anytime, just let off the gas and; if it is safe to do so, tap the + paddle if you have one. This also puts the car in the “coast” mode until you input either brake or throttle; at which point the car already has the gear ready for you. Pretty clever really.
On my work commutes when I don’t feel like burning money unnecessarily, I cruise at 55 and use the coast mode a lot. One day I managed to get my A4 SLine up to 66MPG. And then on the weekend, it’s back to 19MPG 😉
Not sure if any other manufacturers have this, would be interested to know 👍🏼
Best way to sum it all up is: keep your feet off your brake pedal AND your gas pedal except when absolutely necessary. You convert energy of momentum to heat when you press the brake pedal and you use gas anytime you press the gas pedal. Obviously you have to press the gas pedal to get anywhere, but anytime you can avoid pressing the gas you should and anytime you can avoid pressing the brake you avoid converting movement to heat.
Love this channel. It had taught me a lot of engineering concepts and inspired me to start my own UA-cam channel. I would love some feedback and support.
Amazing
Triple like this one. I always wanted to find an efficient way to communicate exactly this to people. Now, I can just reference it. I call it a "red light race" as drivers are competing, who will be at the red light first and sitting there with engine idling. Similar to the hill racing. This, btw, shows that using cruise control is not the most efficient way of driving. Thank you very much for this video! Love it!
Why my mileage is so bad? Because I love how my engine sounds on high RPM. (BMW 3.0 L straight-six engine)
k s exhaust leak
I have another "technique" for myself: don't talk to your passengers while accelerating. I notice that I can basically pay full attention to 2 things at a time while accelerating, and those are ideally proper control of the car and the traffic around you. When I talk to someone next to me, I find I still pay full attention to the traffic around me and to the conversation. This results in shifting from 2nd to 3rd at around 40 km/h instead of 30, and 3rd to 4th at around 45 km/h instead of 35. Fortunately it's still safer than not paying attention to the road, but it does cost fuel.
I would love to see an explanation involving using cruise control at lower speeds in the city between lights and also how to get the best fuel efficiency when driving a manual transmission because they are still out there
It’s all part of the theory we learned in driving school in Germany.
Learning and doing are two different things out on the street :D
Is it? I haven't driven in Germany but I've driven in Italy and Austria around ski resorts where there are quite a lot of German drivers as well and I was left with the impression that they don't really think about driving efficiently. They were constantly just going fast and then slamming on the brakes when they needed to slow down. I guess when you drive a 100k$ Audi which can stop well even on wet roads you just forget how important the way you drive actually is.
LeGendRarY yes I can confirm that. Most people don’t care about efficiency but as I made my driving license learning efficiency was part of it.
@@peterm3861 In Finland they teach it in theory and in practice. And also they show how much your consumption dropped after focusing on economic driving.
I watch drivers and can come to no other conclusion that folks just don’t care about fuel efficiency. Jack rabbit starts and then pour it on until shut it down wearing brakes, straining transmissions and PVC systems. I don’t drive like an old man, but am proud that my 2012 Acadia with 162,000 miles still has original pads and rotors.
My GLA45 actually has a coasting (Merc badge it “glide”) mode. It’s very effective and cleverly designed. But as a fuel consumption reduction aid the engine is so wonderfully powerful you can’t really tell the specific results at the pumps.
Sadly I spent all my time typing this and then turning the sound down as my wife’s says “what rubbish are you watching now?” So I have to re-watch the whole session. Now was that very efficient......
I think there is an error in Velocity cubed. Should be simply velocity squared from drag formula as we do not mix velocity measured against relative wind and car velocity measured against ground. Aerodynamic drag formula is against relative wind and it is simply velocity squared. May vary due to headwind/tailwind but not due to groundspeed.
The hill scenario is where I will always defend a high torque/long stroke motor. So much easier to keep revs down low when climbing a hill vs a short stroke engine that makes it's power on higher RPMs.
During your engine braking example, you indicate that the car uses no fuel until the car is idling at the stop light, but my car continues to idle while coasting towards the stop light and idling uses fuel. Additionally, my Charger, with its 8 speed transmission, likes to downshift as it is coasting. Each downshift raises engine RPMs and I would think that would increase fuel use.
I just got done smoking some delicious zkittles from Alien Labs rolled in a swisher sweet. I kept it simple today, it’s the little things. Anyways the equation you have on the board is a simple one of course but nevertheless, in my 26 years of life I haven’t really cared of enough to try and understand these type of equations but today, a cold dry morning, I understood the equation. Very well put sir.
Highway cruising, every vehicle has a "sweet spot", the RPM in high gear where the engine is the most fuel efficient. In my vehicle that's at 2100 RPM which is 78 MPH or so. I used to drive thousands of miles a year on long highway trips. I set the cruise control at different speeds and checked my mileage. Slowing down to 70 MPH from 80 MPH cost me about 10% in milage.
So, vehicle speed was the only factor that contributed to this increase? Fuel quality, ethanol content, wind direction, tire inflation, tire brand, elevation changes, cargo/load, A/C, alignment, engine tune...you controlled for all of these and still had a reduction in fuel economy despite what every study has ever shown? That's weird.
I do most of this, get an average of 52 mpg in an 2018 Elantra mix of around 40% city and 60% highway driving, record was 61.8 mpg on a tank but that was 90% highway driving.
Great tips!
From what year do cars not use any gas letting go of the pedal in automatic transmission?
Thank you so much, I was seriously wondering about engine efficiency graph. Can you please do more of that in the future?
Disregard my last comment for the fact that I just scrolled down and saw you had posted a video already regarding manual transmission and shifting for fuel economy LOL
I use the eco mode indicator in my corolla to govern my acceleration. I only go to the top of the eco if I have to merge or make a turn. Overall, most people are just flying around in a constant race and not even thinking. It’s no way to live, although I was one of those people for decades.
How to do engine braking?
1) gears should be in engage position or gears should be in Neutral position
2) if gears are engaged then whether I have press clutch pedal or not?
I try to time traffic lights to where I never have to stop... When possible and not being rude to other drivers.
VW has great info you can watch to achieve better mileage. One is watching instant mpg. Many times coasting in 5th gear (in a manual) is better than coasting in 6th because the computer will shut off fuel in 5th and not 6th.
Ive been doing all of this already. Just by logic alone. Weird. I don't think about it or know the mechanics, i just felt it was right and i generally follow my gut.
I have done these techniques for years. Never knew why i got great gas mileage. Everyone always wondered why i could get 42 to 45 mpg out of a 2010 Hyundai Accent. If im not mistaken it was only supposed to get 36mpg on the highway. 🤔
In other words just remember people get mad if you go 2 mph under the speed limit.
Or take too long getting to a red light just so you all can wait at it.
People are really just something special.
3:30 Point of order, it's polynomial (more specifically cubic) increase, *not* exponential increase. Exponential would be if the velocity was in the power, like say 3^v.
I wish this is added to the DMV exam. Every driver must learn this.
awesome,. helps me as a beginer!!! and i always do that, especialy on stops, when i see its red or i go near like 100m like i let gas pedal and when i feel it req i brake slowly trough the first car i see
Would love a video on the differences between ICE and Electric for driving efficiently
Pretty much largely the same, except BEVs can recover energy from regenerative braking (the electric version of engine brake),
appreciate the closing message. I could yap for hours on this subject but you kept it short and sweet 👍
Does he take video recommendations anywhere?
A few years back when I worked MC dispatch I used to do a semi regular run from London to Leeds - a run of roughly 200 miles
My bike - if ridden conservatively in a straight line - i.e a nice leisurely 65mph on the motorway - had a range of just over 200 miles.
At 80mph the range dropped to about 160 miles.
So If I decided to race up to Leeds, it meant I couldn't make it on a single tank and I'd have to stop on the motorway where fuel was considerably more expensive and which also meant I didn't have enough fuel for the return journey without a second fuel stop.
So I could drive faster, give myself more stress, make more stops, and spend more money - or drive slower spend less money make less stops and have less stress - and still do the round trip in more or less the same time.
Driving faster is not a substitute for good journey planning
"The amount of power that you need to produce increases exponentially as your speed increases because the aerodynamic power required is a function of velocity cubed". I think you meant "rapidly" there instead of "exponentially". Last time I checked, exponential was exponentially more rapid than cubed.
On the hill scenario. There are variables missing from that analysis. Time, distance, and fuel consumption rate. Assuming fuel consumption is the dependent value speed, time, and distance would be i independent values. The absolute value for each standardized coefficient of the independent variable will sign the variance each coefficient has on the dependent variable. This will give an accurate answer to the questions. Maintain speed up the hill or decelerate as you go up the hill to reduce rate of consumption. N E how, I’m no expert but I thought I would give some input for consideration. If I was rally racing or mapping my route I would compute this for the terrain I will travel to maximize my fuel consumption. 😊
I literally do all of these things already... it just about keeping momentum and being smart.
Not so much "smart", but aware and motivated. My motivation is to remit the least amount of fuel taxes to the government to waste.
Finally, there are so many videos with bad tips. There are so many people that does not say that engine braking is better for economy
ME: coast to red traffic light
PEOPLE BEHIND ME: ANGER!!!
Not sure if anyone has stated this too, but also should be keeping in mind the amount of stops one would make for gas only. Let's say you have a 400 mile range at 65mph, but at 75 one only has 330 mile range per say. Now take in you are doing a road trip of 375 miles. That equates to one fill up you'd have to make if going 75, which is now a loss in time. You might end up evening out your time gained with your time lost in filling up. So it's just a waste in money.
Engineering Explained how do we identify whether the given car have turbo charger or not both from bonnet and as well as when driving. Please make a video on that bro