Hello everyone! Inevitably, whenever I post a video about octane ratings, viewers outside the US inform me of how poor our fuel is (95+ Octane in Europe vs 87+ Octane in the US). That's not really the case, we use different scales (AKI vs RON), explained here: ua-cam.com/video/zf-OYXlhJis/v-deo.html Don't worry, we're all getting the same stuff, good or bad. Hope everyone's day is going well!
I did a 2400 mile road trip for Thanksgiving and decided to run a premium/regular test in my '11 Mustang GT using premium for the 1200 miles out and regular for the 1200 miles back. Premium fuel gave about 1.5% better mileage, supporting your tests with some real world observations. Since the car happily uses regular fuel without a hint of detonation, I see no need to spend the extra $$$ for premium gas.
Great video. Finally real information about fuel grades. I'm tired of the idiots saying premium or hi-test is just a waste of money. Used to be the case years ago. But today cars are running higher static compression ratios. (Around 14:1 vs 8.8 average). The cylinder pressure is about the same or higher depending upon the load. So today new cars are way more sensitive to octane than they used to be. Keep up the good work.
Dude this data is amazing! Every question possibly to be asked regarding the effects of fuel grade answered! And no your not too nerdy as you've mentioned in your other 10 things about the hellcat car video 😅😂
Engineering Explained one thing also is if you're going to say something is a reference your representing like AAA it's best to include a link to the information or study. Or it's just really hearsay. So where is the link to this AAA study?
Something I’ve recently learned is that here in the UK; our 95 octane is now entirely E10; and our 98 octane is E5. After months of self trials; I’ve discovered that the increased mpg I get from E5 compared to E10 warrants the extra expense in buying the 98 E5. After doing some calculations regarding the mpg difference in E5 to E10, it works out 1 penny per litre more expensive than E10 in real terms.
Thank you for this video. I have been telling this to people for years. Read your car manuals. Now since i got my subaru tuned on the dyno I have to use 93. Of couse only a few people would have their cars retuned. But one of my old cars asked for 87 but would still knock badily up hill. By putting in 93 helpped minimize that. Every once in a while a gas station would water down their gas to save money. This will make your engine knock and bring down the octane level.
Just an example story, here. After we'd bought a new 2002 WRX, my wife, inadvertently, filled it with 'regular' unleaded. Within a short time it threw an engine warning light. Because it was new, we hurried to the dealer to see what was wrong. I don't remember the exact code, but the service writer asked what fuel we were using. My wife said she'd just put regular in it. The guys frown was classic. He went about a dumbed-down explanation as to why that was not a good idea. He was actually pretty nice about it. And did show my wife that right there at the filler cap it said "premium fuel only". The wife was pretty embarrassed, but took it well. She never did that again. So, my take is that in the 2002 model, the car was incapable of making a timing adjustment and just threw a code. If I recall, they did put another O2 sensor in it. My only point, here, is to be aware that not all cars can down-grade to 'regular' fuel gracefully. Especially turbos.
Correct (and unfortunate story, but glad everything worked out). Some cars are labeled "premium required" in which case you don't have the option to choose, if you want the engine to run properly.
Rick Noah So What You're Saying Is That Anything With A Turbo--You HAVE To Put Premium In It, Right? For The Canadian Turbo Geo Metro (Yeah I Know, Pontiac Firefly For You Canadians!) Chevrolet Sprint Turbo MK1, Buick Regal Grand National 231 V6, Pontiac Turbo 301 Trans Am, You Gotta Put Premium In These Too???
Richard Kaltenbach - uh no. I thought I was being specific to the WRX, especially the 2002 model- which can't tolerate 'regular' at all. I would think it would all be relevant to "how much" boost vs. "if" the timing can/will adjust down. The WRX really needs that octane.
I have a 2003 wrx and I can confirm that it states premium fuel only, I would be extremely down on myself if I accidentally put regular in it 😂. Unfortunately, the highest octane where I live is only 90. I’ve been told that the bugeye models were tuned for 93 octane from the factory, maybe someone can confirm that?
I’ve only used top-tier, 93 octane fuel since I bought my 2018 Civic EX-T eleven months ago (although the recommended is Regular). The main reason is to mitigate carbon buildup in the valves of this Civic’s 1.5 liter turbo GDI. Not sure if it does any good but at least it’s not doing any harm. That, in combination with frequent (earlier than recommended) oil changes will hopefully keep it performing at the highest level.
Another dependency that I did not see here was OAT. Owners of the SS sedan (LS3 V8) report similar fuel economy between grades, but as soon as the weather warms you need the higher octane to prevent knock. The OM recommends 91 octane (AKI) minimum, so that’s what I run. Works great, I don’t have to worry about switching gas when weather warms, and I preserve the warranty.
DucFanDan. Haven't noticed that with my cars, but usually see the fuel efficiency drop on winter gas. They change the formula to help with cold starts.
My owners manual states that my 2012 Ford Focus can run on 87 Octane. I need to review it regarding what Octane level it Recommends because with a heavy load or going up a steep incline the engine will knock and not perform as well. I found a significant performance boost without knock at 89 Octane, especially Mobil's Synergy.
Great summary of the research! With a max 3% improvement in power, I'm figuring that the "feeling" of more power I get when I use premium in my Matrix XRS is more psychological than real :P
I once did an experiment with my 2003 4.6 f150 and I noticed a slight power decrease when using 93 octane rather than 87. At highway speed, the engine was having to run at a slightly higher rpm to achieve the same speed when using the higher octane. It’s amazing how engines react when using different types of fuel
This guy is the best. I’m a huge of you man,I’m about to go to automotive mechanic school and there is not much than teachers can show me thanks to you man. You the G.O.A.T.
Another great video as always! Although for sure in the US-- most cars that require premium, when I put a full tank of 89 in do have a noticeable lack of power or smoothness. Good stuff.
it's interesting I never have come across a car that simply recommends premium. I'm sure they exist but like I said the ones I know say "91 or above" or something of the like on the gas cap.
The increasing percentage difference in price between premium and regular is one thing that has always irked me. I remember the price of gas doubling in the mid 2000s, and the surharge for Premium going up even higher percentage wise, despite the fact that that refining costs should have been relatively fixed.
ya so many people don't get this. It is interesting to see how in some states premium is 91, vs others like Texas where I am it is 93 (the worst is California, Nevada, Arizona tho).
I applaud you on your videos. Big fan and a big car / engineering guy myself so I especially appreciate all of the attention to detail you provide in each video. For many years I have been telling people about the advantages of using premium fuel and while most people get it, many will just disagree and thumb their noses at the "Common Sense" approach of using it. Premium provides a superior burn ratio versus lower octane fuels so you receive the benefits of better gas mileage and performance. Unfortunately the higher cost to value ratio is where the waters tend to become a wee bit muddy. This is the part of the argument that most people will never buy into especially if they lease their vehicles with never having the intent of buying them down the road. Truth be told, it would be way too time consuming and expensive to purchase 8-10 test beds over 80 - 100 thousand miles to prove the long term benefits of using higher octane fuels but the results are out there for people that work on cars regularly and see the results of the debris left over on the exhaust values and outer passages in the exhaust system. Way too much to go into here but I know that YOU know what I am saying here. The end result of course being, if you own your car and can afford to pay the additional money, always go for the higher octane and remember at least once a month to blow out the carbon as it’s a killer in the long run. Lastly, with the current ethanol fuels that plague the market today, people should be advised to use STA-BIL in cars that sit around for a while. I also make it a practice to add octane booster on occasion to fuel as today’s fuels lose octane faster than ever because the hygroscopic properties of ethanol keep bringing more and more water into the fuel systems which adds rust to the tank, fuel lines and creates major problems with fuel pumps and injectors. Thanks again for a wonderful video!
First off, as a good engineer you are, thanks for having a source link :) This research was a good effort, but several questions come to mind. Have they reset ignition/ long term fuel trim compensation tables between each run? Did they monitor knock sensor output to ensure accuracy of the tests? I have a hard time believing that Mx-5 showed no difference in performance, unless mazda rolled the car out in a conservative configuration to begin with...
Always read your owners manual. So if you're not going to use the recommended fuel grade for your vehicle, use the proper minimum fuel grade. Some vehicles use mid grade fuel for their minimum fuel grade instead of using regular fuel. Keep up the great work Jason.
For everyone that doesn’t understand yet. The vehicle manufacturers have to comply with the certain Emission standards. They reduced the compression ratios in vehicle to increase fuel economy. The generic timing for vehicles is 20 degrees after TDC because with an increase in timing there is an increase in temperature in the combustion chamber. An increase in temp then increases the production of NOX. Octane rating is just the fuels resistance to detonation. The additives are all pretty much the same so if you put premium in your vehicle that doesn’t require it you’re just wasting money. In higher compression engines or performance engines they require higher octane because they need the fuel to resist detonation. If you put regular in a premium vehicle you may have the chance to have knock in your vehicle. But also if your regular vehicle is knocking you can try putting higher octane to decrease it.
I have never seen this topic communicated so clearly and with excellent data. Seems to really benefit the bigger engines -- not necessarily from a pure cost-to-MPG perspective -- but is cool to know if you're myopic to performance at the expense of cost. Now I want this data on my 2017 V6 Accord!
I remember hearing at some point that it takes cars a few weeks to properly adjust to new fuel (minor re-mapping), which again from memory is why just switching from the lowest octane that your car will take to premium won't yield much benefit, unless you keep using it. Cost wise, you will never save enough fuel to offset the additional cost. Here in Australia the difference between our lowest (non-ethanol) and highest is around 15-20 cents per litre (currently as high was 23.5 cents! which is $159.4 versus $182.9). On a 60L tank that is: $9-$12/ $14.1 (AUD), meaning to get a cost benefit you need to have an increase in range between the 2 fuels of over 100km (based on a fuel consumption of 5.65L/100km also known as about 42 miles per gallon). Which in suburbia is just not going to happen, so if you drive only in the city, the only reason to use the more premium fuels is to keep your engine clean. An oddity that I observed, is that my last car ran better on certain brands of high octane fuel, and on at least 1 brand it caused hunting....
Great video. I've always started with lower octane fuel, and if the car didn't run right or had knocking/preignition issues, I'd move up to mid-grade. If that didn't make it run good, then you know you need premium fuel.
Hi. I have Class C Motor home based on Ford E450 which is V10. I felt a lot of difference between 87 octane VS 93 octane. Since it has 55 gal. tank which is hard to choose premium gas however it performed so well especially on hills that I got premium gas all the time on Utah trip for climbing all the national parks.
My GL1800 sees an incredible difference between hightest and regular!!! It had a terrible hiccup around 3000rpm, and inevitably did it coming out of a corner... which really screws things up ;-) I put hightest in it, and no more hiccups plus I went from 40 mpg to 45 mpg. Well worth it in my book :-) Excellent video, as usual Mr EE :-)
@Boom Kikker We have the same thing in the US with the ethanol being added to gasoline at approximately 10%, really makes it a pain when you go to use anything that has been sitting for a while, especially with carburetor engines, not really an issue with fuel injection.
Hey just want to say as a student of Mechanical Engineering I find your videos really entertaining and educational. I'd love to see one explaining Bluetec diesel. Keep up the good work!
With that it may be due to altitude the closer you are to sea level the higher octane rating fuel they use where as the farther up from sea level you are there is less air so octane rating is reduced
christopher dimotsis and Idk why they still do it that way, that method went outdated as soon as the first computerized fuel injection system came out which compensates for that.
I'm interested to see how the results would turn out for older cars. I have a car from 2004 that recommends premium and I've always wondered how different it would be if I used regular.
Great video as always, I just run what the owner's manual recommends. But it is great to see actual data, so really with a larger engine, you will see some improvement. But, I don't think it's enough to justify the inflated price. Now, if your manual states to use premium, then you're kinda stuck with using it. The engineers that designed the engine, know what they are talking about. I have read stories about people damaging their engine by not using the recommended fuel and then the dealer wouldn't warranty it because they voided the warranty by using the wrong fuel. I learned long ago, you are better off establishing a good relationship with your dealers service department. Even though dealer servicing is higher, in the long run your car will last you much longer, and give you much better service. My wife and I have made friends with the local Nissan dealership, and when we go in for service, they always apply any coupons they have for the service they did. Sometimes they even throw in free stuff. So, in summary, if you plan on driving your car for longer than you financed it, take it to the dealer for service. If you trade cars like every 2 or 3 years, go to Walmart and have it serviced.
It's worth noting that not all of these vehicles necessarily have an engine map that is dynamic in regards to it''s fuel supply, thus you'll see differences in power/fuel economy that are essentially negligible. Also worth noting is the fact that the A3 and the F150 only recommended premium fuel despite both certainly requiring premium for long term reliability (more audibly in the A3 as AAA found out).
I've always ran premium in my cars, because I have always had mercedes or cadillac and don't want to go cheap on luxury style cars. I've mostly done it because in my mind, I think the gas would be cleaner and cause less carbon buildup in the cylinders. Now, I have an Acura and maybe I'll try switching to normal gas for a few months. Thanks for the info.
Sure, it does all that, at the expense of power. Why have a car with any modicum of power, fill i with regular, only to have it stubble all over itself when you floor it?
One of my cars is designed to use high octane fuel. Once, I forgot and accidentally put regular fuel in that car. It started to feel sluggish and was not performing as usual. I was almost ready to take it to the shop before I realized what I had done. I ended up adding some octane booster and it worked fine until the next fill up.
izukenekuzi I didn't want to link his video on octane rating and wanted to leave it up to Jason to provide the information he would like to complement this video.
I used to have a saturn sky redline. It had gm's available lnf tune to bump it from 260 hp and torque to 290 hp and 340 tq. With the tune, you could not run anything below 91 octane or at a full throttle pull, especially in 4th gear when it loaded the engine fully at 23 psi of boost, you would drive straight into knock city. Granted thats from a 2 liter engine so its specific output was high for something designed in the mid 2000's as a regular street car. If you didn't run a cleaning solution through it every 8,000 miles or so it would do the same thing though that could have just been from carbon buildup due to poor fuel quality or the direct injection aspect of the engine. The interesting part about this was how much it effected the escalade. Knowing it can potentially make a difference for MDS equipped vehicles since they can remain in 4 cylinder mode more effectively may make running premium worth it, especially if driving conditions cause it to constantly switch on and off at it's usable threshold. The jeep i have now has the 5.7 with mds (recommended 89 octane running 87) and on a non level highway or with any headwind between 65 to 72 it will sometimes kick on and off regularly.
I always thought that if you have a higher compression ratio then you need 92 octane gas so the fuel and air mixture doesn't explode to early making the engine knock. That's how I always thought about it
Using Premium in my 2014 VW Passat 1.8TSI I see a significant difference in performance and economy. When I run regular it’s sluggish and the economy falls off. Of course here in GA we get the higher Octane Premium at 93. Good video but I’ll continue use Premium for as long as I have the VW.
Here's a good question: Will a car that recommends premium fuel that has been filled up with premium all it's life last longer than if it was filled up with regular all it's life? Are there internal engine cleanliness/maintenance benefits to using premium?
Only way it'll make a difference is from reduced knocking or extra cleaning additives that are usually found in premium fuels. Octane on its own won't make any difference otherwise. Note that in the case of the Audi in this video it could very well make a difference as a lot of knocking was observed with the lower grade fuel.
Assuming that the car can adjust timing based on knock it shouldn't. However if anything were to go wrong and keep it from adjusting the knock would cause damage
IF it gets better fuel economy on premium then I would think because it's evidently burning more effectively that it would be burning cleaner as well but if there is no change in efficiency (mpg) then I don't think it would be burning any cleaner. At least that's my logic and my totally unprofessional opinion.
another very well put together video, love the clear explanations, feel like i learned something from it, took 13 minutes to watch instead of spending a lot more time reading the actual article, keep up the good work
I admire your level of intelligence and modesty. Enjoy your posts. Sadly, videos like this won’t go viral because numbers are crunching and some background knowledge coupled with with a quest for wisdom will be required. Thanks for your posts.
I need to run premium fuel because I have a turbocharged vehicle. Unfortunately, they charge almost a dollar more for it where I live. I'll probably do an E85 conversion in the spring, which only requires an upgraded fuel pump & flash tune. What happened to the days when premium was only 20 cents more? :/
Advertising sometimes implies that higher grade fuels have additional additives depending on the manufacturer. Is there any difference between low grade and premium within the same brand other than octane rating?
MrEE, Manufacturers have many reasons for recommending fuels, fluids, and maintenance routines for their vehicles. It isn't all about power. Perhaps a video on the other benefits/drawbacks of this particular subject would be in order. I know you'd love to discuss exhaust temperatures and catalyst life in relation to timing and octane... which could lead to conclusions about smog tests and warranty issues, etc. Looks like AAA even included the cat temp charts for you.
I would imagine that *any* fuel dispensed into your pants would be very irritating to sensitive skin. But, maybe the manly scent could help attract the ladies. Either way, I hope you're a nonsmoker.
Jason, outstanding video my man! I have a question I hope you will answer for me. I have a 2017 Mustang GT/CS. The manual recommends 87 octane fuel. But I just noticed knocking the past couple of weeks. I've had the car for 5 years and never heard knocking. I guess I should use premium 93 octane now ? Thank you, Dan Reisker
Congratulations! Another professional analysis of yours. You are speaking as a good lecturer. I know what I'm saying - I'm university professor in Poland. Good luck!
My 2000 (purchased new) Dawoo Nubira wagon recommended unleaded when new. The mileage initially was 26-27 hwy and 18 in town. In experimentation i began recording results that i got using various Brands of fuel. No particular difference was noted other than one brand whose reg. unleaded with high amount of detergent additives and a min. of one point octane higher seemed to increase mileage by 2-4 miles per gallon and add power (to the delight of a certain lead foot female with more tickets than me with whom i share driving duties). After the first year i asked our mechanic to check if there was anything he could do to increase mileage..he said everything was 👌 perfect. As an experiment i advanced timing by 3 deg but the computer cancelled the effect out so i reset it. Instead i began using high octane fuel from that same maker. Today after 140,000 miles, very faithful routine maint, and zero engine issues and only one tune up needed we regularly get 33 mpg hwy and 22 city as long as we drive 60-64 / 25-40 resp. It burns no oil..yet.. all i can say is to do the maint that you would do on a ‘65 Chevy rather than the ‘every 12,000’ miles recommended and a newer car will last forever. Our 18 year old Nubira still drives and hums like new, has good power and has never needed any expensive repairs! We plan to keep it until 300,000 miles since it still looks like new!
This video completely confirms my using and recommending premium fuel. Another added benefit are the additives that most premium fuels use which helps to keep clean injectors and many other engine responses, in terms of power and engine smoothness, which could and should help the engine's longevity. The bit more expense using premium over regular octane is well worth the extra cost, in my experience and opinion.
I dont think premium is worth it. If you sum the difference compared to simple regular fuel, it can be a lot of money after a hundred thousand km. It also depends of the complexity and cost of the parts for the engine. One thing is injectors for a regular atmospheric car, other are high pressure fuel injectors in direct injection systems; in the later I would definitely run premium of a reputable brand because the parts cost is much more expensive than the sum of the difference of the fuel over the life expectancy of the vehicle.
I don't think so, Top Tier fuels are certified as Top Tier, but the additives can vary by manufacturer. Even the refineries will put in different additives to fuels going to different brand stations to satisfy that brand's specs. There's also debate on the effectiveness of such additives in GDI engines, where the fuel is sprayed directly into the combustion chamber instead of into the intake runners and on top of the intake valves. For the latter I think a Top Tier fuel would work better to keep things clean. But, I still just put cheap(er) Kroger 93 octane into my Integra GSR. Been using that for 16 years with 362K miles on the original engine (and original injectors and fuel system) so I think it's doing okay.
Patrick94GSR - when I said the same across the board I should have qualified it by saying the additives from the regular to the premium are the same with each manufacturer having their own blend, ie whatever shell uses in their premium is the same as their regular, same with Chevron etc. They makers have their own blends and their blends have to be universal across their octane ratings to be top tier certified. As for top tier certification, that is something the manufacturer pays for so they can advertise it, doesn't mean they are any better, it just means there is a place that tests it and then stamps it that way (just like THX certification, look it up, it is interesting). I too use Kroger lowest octane because not only do I take advantage of the Kroger rewards, but my car runs the best on it. Thanks for helping me clarify my original post.
Thank you so much for this video. I have been hunting around for a while to find a comprobile video that ACTUALLY answered my question of "should i say with 95 or try 98?" (my country uses RON so 87? vs 91 by US standards i think) and all i found was opinions. Thank you for actually using decent and easy to understand data and explaining it so well
I had an old car that knocked going uphill, and high-test gasoline fixed that problem. Then I found that plus grade worked just as well. It only knocked on regular.
Matthew Tyler that F-150 can also tow 13,000 lbs. The tune is different to do a different job. The Escalade is more for passengers. It’s not made to pull that much so it can be tuned for better mpgs.
Hello EE. Big fan of your work :) I live in Poland(Europe) and have I also used in the past premium vs standard fuel and didn't see a difference. Now i have Honda Accord VII 2,4 liters K24A3 with have static CR 10.5:1. It is premium fuel recomended, but not required. I run it on LPG. On sequencial LPG instalation cold engine is running on fuel till temperature of engine achives certian level(about 40 degrees C). After that it switches to LPG. To the point. I run it on Shell V-Power 100+ Octane(Euro rating ofc.) I do it because I noticed that my engine achives working temperature faster(even when LPG is off) and my thinking is because it more efficient(more power with the same ammount of fuel as you pointed in the middle of the board) Just wanted to share my empirical expiriance :) FYI. LPG is 103 octane Euro rating - mayby you want to do video on that
Interesting video. I have an Opel Mokka, Buick Encore to you in the states, with the 1.4T motor and it was interesting to see that it lost power using higher octane fuel. Just picked up the vehicle and I have always trained myself to use the higher octane when it comes to gasoline motors. Last few years has seen my driving diesels, so it was interesting getting back into a gasoline motor. Torque is flipped and it drives me nuts. Great video as always. Keep up the great work!!
The results were presented in a misleading way. The reason the big engines had higher %diff for fuel economy is because they have lower fuel economy. A 1 mpg improvement on a car that gets 10 mpg is 10% better, but if a 40 mpg car gets a 1 mpg improvement it is only 2.5% better. This is why when talking about fuel efficiency it makes more sense to use the perspective of fuel consumption not fuel economy, i.e. use units of [gallon/mile, g/km, l/100km, etc] instead of miles per gallon. Its the same reason you do thermodynamic calculations using absolute temperature [K] instead of relative temperature [deg C, deg F] I have questions about the test methodology as well. Some of the engines had almost no spark advance for the high octane fuel, so did AAA properly prep the vehicles so the ECU updated fuel trims? If they didn't how was the car supposed to know it could spark advance without knock?
Well spotted. Not sure if it was done intentionally but it is relevant. Also the numbers didn't reflect the improvement in the power and torque curves of the MX5 across the entire range. Still it does not explain the performance loss or the audible audi knocking O_o
I don't understand what you mean. If you're trying to figure out if it's worth it to buy premium gas, of course you want to compare your efficiency gain % with extra cost %. How is that misleading?
I'm not sure I understand your argument about fuel consumption vs fuel economy. One is just the inverse of the other, so when you describe the differences in % you still have the same problem. So in your example the car with poor efficiency would see it's consumption decrease by 10%, and the other car would see it decrease by 2.5%. Anyway, it's not really a problem because you want to describe the changes as percentages. It's not at all the same issue as you have when you use celsius/fahrenheit instead of kelvin. Celsius and Fahrenheit have arbitrary 0 values, that's why it doesn't make sense to use them in thermodynamic equations.
In my NC I feel the difference on full throttle. In my Mazda 3 Skyactive, I feel a hick, and logging timing to the laptop, you really see a step in ignition timing on RON 95. Use RON 98 (93) in both cars now.
Great review. A couple of points may have some merit. 1 intake airflow using premium at higher rpm uses less o2 vs regular this may also contribute to increased gains. 2nd my veloster is listed as regular however gains are noticed , without premium minor pulsing is experienced, I suspect hyundai set ecu to accept higher octane. Would have been nice to see the test on a gm ls3 that has two mappings with stock ecu
It's always been the case that different engines designs respond better than others to higher octane and performance tuning. Since the introduction of fuel injection and the addition of knock sensors this has become less transparent to owners and mechanics hence the misinformation, over simplifications and generalisations that now abound. It great to see a study like this which puts the spotlight onto the manufacturers and how much their engine design can benefit from optimal conditions (fuel). I run Mobil 1 synthetic oil and Mobil 98 RON fuel in my Merc CLK320 to give it the best chance of performance, efficiency and reliability. Very happy with the result.
I would like to add something. Compression ratio also play a huge part in using octane diff. Like Mazda skyativ engines. It is recommended to use 95(Asia) but there is a huge diff when using premium(vpower) Turbo charged also have huge diff when using premium fuels If your compression ratio is low like SSS(12:1), there isnt any huge diff. But like I was saying, for Mazda skyactiv models(14:1) there is a huge benefit. You can try.
Can you do a video on octane booster juice? I would love to see how much various engines can benefit from like 108. From this video it seems a huge NA engine would be most likely to benefit. Do turbo racing engines really benefit from high octane then?
There is only one “Octane Booster” product I know of (and have personally used), which actually works. It’s called *“Race Gas”* (unoriginally enough); and when mixed with 93AKI, can make up to 105 octane at full concentration. All *UNLEADED,* of course. *EDIT:* Pretty much any “108” you speak of, will contain Lead and thus, is not suitable for roadgoing / emissions-controlled engines. The *Race Gas* product is rather expensive to boot, and not something most people are likely to run on a daily basis. Much like actual, purpose-crafted racing fuels.
wow, fascinating video Jason, i really appreciate the work...I have a 2004 tacoma with a 2.4l and toyota recommends premium to help reduce carbon buildup so i use 91 and I can still hear a slight ping when pushing the motor hard as if the computer is giving it as much advance as it will take but my wifes 2011 camry with a 2.5 runs great on regular...I have to admit I have never read her owners manual but the one or two times I ran high test it didnt seem to make any difference.
Great video, I have a 2008 mx5 and I think that the reason why the numbers didn't change is because premium fuel is manufacturer recommended or required. Besides the owners manual saying it, there's also the gas door which says premium fuel. This is if you were taking manufacturers mpg rating into consideration. But very much makes sense to me now. Thanks Ohio!
Can't measure it directly (although that would be cool) - ECU's will advance ignition to the point where it starts seeing knock, then backs it to a safe level. Thankfully, modern knock sensors & detection algorithms are very good.
With proper ECU programming (sort of chip tuning) you actually can get a significant improvement in power by using fuel with higher octane rating. For example my Audi A4 B7 1.8T had 163hp and 225Nm as stock with 95E octane fuel (I'm using the European RON-scale). With stage 1 program numbers increased to 185hp and 300Nm with 95E and 198hp and 320Nm with 98E fuel. 6,6% differnce in power by increasing octane number. Now my car was re-programmed for E85 fuel (bioethanol) which is equivalent for 105-106 octane fuel. Car produced 224hp power and 387Nm in torque. 27,2% increase in power in total by using fuel with higher octane rating and programming the ECU to match the fuel. Car has been dyno tested with each fuel with the same dyno. Only mechanical upgrade are the injectors which has been replaced to match the amount of fuel injection with E85 (avg. 20-25% higher fuel consumption due to smaller energy content).
Do you guys have difference in ethanol percentages in "regular" vs. "premium"? If so, there might be some other long term issues with using cheaper fuels.
I've tested both regular and premium where I live with a cheap ethanol test kit and they were always 10% ethanol. The only change from that are special fuels we have here. One is E15 with 15% ethanol sold at only a handful of stations and we have 1 station that sells E85 which is 85% ethanol. That blend is pretty rare here though, like I said only one station. This is in Dallas, TX USA.
Currently where I live, in some places premium fuel is cheaper, because of a price spike of regular (regular is 2.07 NZD per litre) so we are paying just under US 5.50 per gallon of regular, but premium was 2.05 NZD/L where I filled up, so it was 5.44 USD per gallon.
Some gas stations are worse than others. If I leave work and fill up in the rich folk area, I'm paying a high price for premium. Get closer to home and premium can be $.40 cheaper.
depends on where you live! I live in Mid Missouri and our Premium price mark is $0.40 higher than the regular price. I drive a hybrid and apperently they love Premium fuel! I get about 18% MPG improvement when using Premium, so unless the gas market suddenly crashes and regular goes down to $1, it will be more benificual for me to stick with Premium!
I think it depends on the average ambient temperature, compression ratio of the engine and cylinder shape (is it under or over square), type of injection (Port or Direct) and if it has forced induction or not and materials used. And that is all dictated by the purpose of the vehicle. Bottom line is how much heat the engine can handle is what dictates the type of fuel used. I mean, like the Jeep if running at X boost on regular fuel will take X microsecond to ignite fully but with premium fuel that has a higher knock rating, will take X+ microseconds to burn therefore energy released by X amount of fuel is not utilized like when using regular fuel. However, if the tolerances are too small, premium fuel requirements is there to protect the engine and not to produce more power. Power is a by product though of the smaller tolerances so it is tricky. What I do is I use or 98 octane premium fuels in long drives or if I expect to rev over 3000RPM but if I know I will be driving only in the city, then I will just use 95 octane. We are still have 90+ F or 32+C days here considering it's December already.
Good info here Jason ! I use premium a bit simply because I don't burn through a tank of fuel in a month. With fuel sitting int he tank for 30+ days and the Midwest having this ethanol stuff, I didn't want to take chances of the water separation issue. Maybe an idea for a video ?
yup you sure can. my 2016 chevy colorado with a 3.6 requires 87. but now with just over 70k miles with 87 the engine spark knocks ( rattles ) at low rpm and a light load. slow accel from a red light. running mid or high grade stops this annoyance. but yea it will not hurt your engine to run higher octane.... just your wallet due to its price difference.
My evidence is anecdotal, but works for our vehicles. 13 Altima 2.5. Recommends 87, at our altitude of use (between 2000 and 8000 ft above sea level, primarily 5100 to 5400 ft), every dealer for our car stated 85 will work just fine. Use a Top Tier gas, preferred brand has only 85 or 91. 10 tanks of 85; felt like a typical balanced shaft 4 banger; shakes at hot load idle (stop, foot on brake, a/c on) but otherwise felt.......normal. Then, 10 tanks of 91 from same station. Wife noticed hot load idle felt smoother to her; I noticed the steering wheel buzzed less. Perception was run up the passes more at ease. Fuel economy went up about 8% (may be attributed to continued engine break in). After a few cross country runs (summer with passes over 9500 ft, including Eisenhower, Vail and Monarch in Colorado) with zero problems, all the power wanted for getting up the passes, tried 85 again, same brand. Within half of a tank, wife asked what I had messed up in her car; went back to 91, and 92,000 miles later, very satisfied and will never put less than 91 in that particular vehicle. Whereas 2008 Sierra with Vortec 4.3......it couldn't care less if it is 85 or 91; did the same type (with fewer tanks) experiment. To me, each vehicle, although the same model and engine, is an individual and results can vary.
gea g37 are pretty high compression cars and if it says premium required then deff deff put it in youl also feel a power loss in the upper rpms with regular.
Nice summary of this study, which does a good service to those who drive a car with merely a recommendation for premium fuel, as opposed to a strict requirement for premium. I'm glad to see that you emphasized this point for the benefit of those who missed it. I do have some questions about the 25 percent price difference between regular and premium, as I've only observed differences of less than ten percent in my region.
% increase in performance varies wildly. The difference between 89oct and 93oct on a midlevel boosted car like a m3 would be 50 or even 75hp even stock, that's a big difference
Best used in cars with higher compression, be it dynamic or static, along with more agressive cam profiles and higher flowing heads. The whole purpose is to mitigate pre-detonation. Whole reason people run alcohol in dragsters, as well as the cooling aspect of how much of it gets pumped into the cylinder
Would be good to see one of these comparisons where a performance build car (drag, drift, time attack) gets tuned on the different fuels and seeing how much difference it makes, just using the stock computer too vary the timing etc won’t get as much gain as a tuner with a good ECU
Awesome video. Can’t believe I only saw this now. My 2016 crosstrek says in the manual to use RON 90 minimum. The filler cap has a sticker recommending RON 95. In the long run is it worth having to pay extra for what the 95 fuel offers over the 91 fuel?
Hello everyone! Inevitably, whenever I post a video about octane ratings, viewers outside the US inform me of how poor our fuel is (95+ Octane in Europe vs 87+ Octane in the US). That's not really the case, we use different scales (AKI vs RON), explained here: ua-cam.com/video/zf-OYXlhJis/v-deo.html
Don't worry, we're all getting the same stuff, good or bad. Hope everyone's day is going well!
I thought everyone knew something so basic
Cheers! =)
You would be wrong. Before his video I was the disgruntled mob raging about low octane. This channel is informative AF!
Not to mention the people still thinking octane rating is just how much oxygen is in the fuel
I understand the difference better.
In France we have 95, 95 + E10, 98, 98 Premium (with additive) and E85
If you drive a Honda Civic, I highly advise you to Fill your half of your Tank with Shell V Power and Chevron Techron so your engine can run V Tech.
You do realize that Hector is running 3 Honda Civics with Spoon engines?
And don't even get me started on the T66 turbos
Top Tier comment right here 😏😏
Stock filter + 5/30 full synthetic. No additives.
Why would that help?
I only use racing fuel in my Prius.
StrangeClouds what race fuel do you use and what Octane
might be electricity generated by Atomic power.
Racing Fuel is really good for your fluxx capacitor, er
I tried Kerosene and I gained 20 hp from the electric motor alone ;)
that is fine, just fill the inside with premium, and toss a match in the Prius
I did a 2400 mile road trip for Thanksgiving and decided to run a premium/regular test in my '11 Mustang GT using premium for the 1200 miles out and regular for the 1200 miles back. Premium fuel gave about 1.5% better mileage, supporting your tests with some real world observations. Since the car happily uses regular fuel without a hint of detonation, I see no need to spend the extra $$$ for premium gas.
Great video. Finally real information about fuel grades. I'm tired of the idiots saying premium or hi-test is just a waste of money. Used to be the case years ago. But today cars are running higher static compression ratios. (Around 14:1 vs 8.8 average). The cylinder pressure is about the same or higher depending upon the load. So today new cars are way more sensitive to octane than they used to be. Keep up the good work.
Dude this data is amazing! Every question possibly to be asked regarding the effects of fuel grade answered! And no your not too nerdy as you've mentioned in your other 10 things about the hellcat car video 😅😂
Glad you enjoyed it! AAA did an awesome job with this study.
Engineering Explained one thing also is if you're going to say something is a reference your representing like AAA it's best to include a link to the information or study. Or it's just really hearsay. So where is the link to this AAA study?
It's in the video description there, big guy.
Something I’ve recently learned is that here in the UK; our 95 octane is now entirely E10; and our 98 octane is E5. After months of self trials; I’ve discovered that the increased mpg I get from E5 compared to E10 warrants the extra expense in buying the 98 E5. After doing some calculations regarding the mpg difference in E5 to E10, it works out 1 penny per litre more expensive than E10 in real terms.
Never seems to make a difference in my car. But it's only a 1litre turbo so maybe that's why
Thank you for this video. I have been telling this to people for years. Read your car manuals. Now since i got my subaru tuned on the dyno I have to use 93. Of couse only a few people would have their cars retuned. But one of my old cars asked for 87 but would still knock badily up hill. By putting in 93 helpped minimize that. Every once in a while a gas station would water down their gas to save money. This will make your engine knock and bring down the octane level.
Just an example story, here. After we'd bought a new 2002 WRX, my wife, inadvertently, filled it with 'regular' unleaded. Within a short time it threw an engine warning light. Because it was new, we hurried to the dealer to see what was wrong. I don't remember the exact code, but the service writer asked what fuel we were using. My wife said she'd just put regular in it. The guys frown was classic. He went about a dumbed-down explanation as to why that was not a good idea. He was actually pretty nice about it. And did show my wife that right there at the filler cap it said "premium fuel only". The wife was pretty embarrassed, but took it well. She never did that again. So, my take is that in the 2002 model, the car was incapable of making a timing adjustment and just threw a code. If I recall, they did put another O2 sensor in it. My only point, here, is to be aware that not all cars can down-grade to 'regular' fuel gracefully. Especially turbos.
Correct (and unfortunate story, but glad everything worked out). Some cars are labeled "premium required" in which case you don't have the option to choose, if you want the engine to run properly.
Rick Noah So What You're Saying Is That Anything With A Turbo--You HAVE To Put Premium In It, Right? For The Canadian Turbo Geo Metro (Yeah I Know, Pontiac Firefly For You Canadians!) Chevrolet Sprint Turbo MK1, Buick Regal Grand National 231 V6, Pontiac Turbo 301 Trans Am, You Gotta Put Premium In These Too???
Richard Kaltenbach No, that's not what he is saying.
Richard Kaltenbach - uh no. I thought I was being specific to the WRX, especially the 2002 model- which can't tolerate 'regular' at all. I would think it would all be relevant to "how much" boost vs. "if" the timing can/will adjust down. The WRX really needs that octane.
I have a 2003 wrx and I can confirm that it states premium fuel only, I would be extremely down on myself if I accidentally put regular in it 😂. Unfortunately, the highest octane where I live is only 90. I’ve been told that the bugeye models were tuned for 93 octane from the factory, maybe someone can confirm that?
I’ve only used top-tier, 93 octane fuel since I bought my 2018 Civic EX-T eleven months ago (although the recommended is Regular).
The main reason is to mitigate carbon buildup in the valves of this Civic’s 1.5 liter turbo GDI. Not sure if it does any good but at least it’s not doing any harm. That, in combination with frequent (earlier than recommended) oil changes will hopefully keep it performing at the highest level.
Hey after five years is your honda still running?
I have a '99 1.8t runs fine in mid grade, but I can definitely feel the difference when I tried the lowest octane, the power drop was considerable.
Great video as always! Hope you do one comparing US standard ethanol mixed 10-15% ethanol vs ethanol free fuel.
Another dependency that I did not see here was OAT. Owners of the SS sedan (LS3 V8) report similar fuel economy between grades, but as soon as the weather warms you need the higher octane to prevent knock.
The OM recommends 91 octane (AKI) minimum, so that’s what I run. Works great, I don’t have to worry about switching gas when weather warms, and I preserve the warranty.
DucFanDan. Haven't noticed that with my cars, but usually see the fuel efficiency drop on winter gas. They change the formula to help with cold starts.
My owners manual states that my 2012 Ford Focus can run on 87 Octane. I need to review it regarding what Octane level it Recommends because with a heavy load or going up a steep incline the engine will knock and not perform as well. I found a significant performance boost without knock at 89 Octane, especially Mobil's Synergy.
Great summary of the research! With a max 3% improvement in power, I'm figuring that the "feeling" of more power I get when I use premium in my Matrix XRS is more psychological than real :P
I once did an experiment with my 2003 4.6 f150 and I noticed a slight power decrease when using 93 octane rather than 87. At highway speed, the engine was having to run at a slightly higher rpm to achieve the same speed when using the higher octane. It’s amazing how engines react when using different types of fuel
This is logically flawed.
This guy is the best. I’m a huge of you man,I’m about to go to automotive mechanic school and there is not much than teachers can show me thanks to you man. You the G.O.A.T.
Haha, very kind words, I really appreciate it! Best of luck to you in mechanic school!
Been there done that. Waste of time and money
Lol GOAT. Yeh they guy is very knowledgeable and helpful but I wouldn't go as far as GOAT, he's only been around few years lol
4th reason: In Canada, if you want ethanol-free gas, you have to either buy Shell 91 V-Power, or Chevron 94 Premium Plus.
Wow...94...Another reason to go to Canada.
does the other reason start with a T? hahah
canadian tire 91 is also ethanol free and only BC gets chevron 94
kimbo slice interesting; we don't have and CDN Tire gas bars near us.
Buff Barnaby there's also Petro station that has 94 octane
Another great video as always! Although for sure in the US-- most cars that require premium, when I put a full tank of 89 in do have a noticeable lack of power or smoothness. Good stuff.
it's interesting I never have come across a car that simply recommends premium. I'm sure they exist but like I said the ones I know say "91 or above" or something of the like on the gas cap.
This is a new thing because adjustable timing has not typically existed to this level.
@@DFWsCars modern fords say “minimum 87, 91 recommended”
The increasing percentage difference in price between premium and regular is one thing that has always irked me. I remember the price of gas doubling in the mid 2000s, and the surharge for Premium going up even higher percentage wise, despite the fact that that refining costs should have been relatively fixed.
Before everyone not in America thinks our fuel is inferior, we use a different scale.
91 =95
93 =98
95=100ish
I think
ya so many people don't get this. It is interesting to see how in some states premium is 91, vs others like Texas where I am it is 93 (the worst is California, Nevada, Arizona tho).
The good ol' (R+M)/2 method confuses many.
+Space Ghost
thank you for that explanation. i was confused too
98 is the highest, if gets to 100s it's called race fuel which should not be used on a regular engine
Thanks, had no idea! However calling 95 premium still sounds a bit odd... 98 and upwards is what's considered premium here.
I applaud you on your videos. Big fan and a big car / engineering guy myself so I especially appreciate all of the attention to detail you provide in each video. For many years I have been telling people about the advantages of using premium fuel and while most people get it, many will just disagree and thumb their noses at the "Common Sense" approach of using it. Premium provides a superior burn ratio versus lower octane fuels so you receive the benefits of better gas mileage and performance. Unfortunately the higher cost to value ratio is where the waters tend to become a wee bit muddy. This is the part of the argument that most people will never buy into especially if they lease their vehicles with never having the intent of buying them down the road. Truth be told, it would be way too time consuming and expensive to purchase 8-10 test beds over 80 - 100 thousand miles to prove the long term benefits of using higher octane fuels but the results are out there for people that work on cars regularly and see the results of the debris left over on the exhaust values and outer passages in the exhaust system. Way too much to go into here but I know that YOU know what I am saying here. The end result of course being, if you own your car and can afford to pay the additional money, always go for the higher octane and remember at least once a month to blow out the carbon as it’s a killer in the long run. Lastly, with the current ethanol fuels that plague the market today, people should be advised to use STA-BIL in cars that sit around for a while. I also make it a practice to add octane booster on occasion to fuel as today’s fuels lose octane faster than ever because the hygroscopic properties of ethanol keep bringing more and more water into the fuel systems which adds rust to the tank, fuel lines and creates major problems with fuel pumps and injectors. Thanks again for a wonderful video!
First off, as a good engineer you are, thanks for having a source link :)
This research was a good effort, but several questions come to mind.
Have they reset ignition/ long term fuel trim compensation tables between each run? Did they monitor knock sensor output to ensure accuracy of the tests?
I have a hard time believing that Mx-5 showed no difference in performance, unless mazda rolled the car out in a conservative configuration to begin with...
Always read your owners manual. So if you're not going to use the recommended fuel grade for your vehicle, use the proper minimum fuel grade. Some vehicles use mid grade fuel for their minimum fuel grade instead of using regular fuel.
Keep up the great work Jason.
Yeah, I'm pretty tired of paying 50 cents more per gallon. I would love to use regular fuel, but my WRX requires 91 octane at a minimum.
Pay to play with a higher compression better performing engine...get an Impreza!
For everyone that doesn’t understand yet. The vehicle manufacturers have to comply with the certain Emission standards. They reduced the compression ratios in vehicle to increase fuel economy. The generic timing for vehicles is 20 degrees after TDC because with an increase in timing there is an increase in temperature in the combustion chamber. An increase in temp then increases the production of NOX. Octane rating is just the fuels resistance to detonation. The additives are all pretty much the same so if you put premium in your vehicle that doesn’t require it you’re just wasting money. In higher compression engines or performance engines they require higher octane because they need the fuel to resist detonation. If you put regular in a premium vehicle you may have the chance to have knock in your vehicle. But also if your regular vehicle is knocking you can try putting higher octane to decrease it.
_Hey, that smells like regular. She needs premium, dude! PREMIUM! DUDE!_
Oh man, what's this from? It activated some neurons that have been dormant since childhood.
@@fuzzydunlop7928 Simpsons, Season 9 Episode 9. Homer buys Snake's car, Lil' Bandit.
I have never seen this topic communicated so clearly and with excellent data. Seems to really benefit the bigger engines -- not necessarily from a pure cost-to-MPG perspective -- but is cool to know if you're myopic to performance at the expense of cost. Now I want this data on my 2017 V6 Accord!
My fuel cap says “95 RON min” (Europe) i’ve started using 99 RON recently and the engine is noticably quieter and smoother, and it costs only 5% more.
I remember hearing at some point that it takes cars a few weeks to properly adjust to new fuel (minor re-mapping),
which again from memory is why just switching from the lowest octane that your car will take to premium won't yield much benefit, unless you keep using it.
Cost wise, you will never save enough fuel to offset the additional cost. Here in Australia the difference between our lowest (non-ethanol) and highest is around 15-20 cents per litre (currently as high was 23.5 cents! which is $159.4 versus $182.9).
On a 60L tank that is: $9-$12/ $14.1 (AUD), meaning to get a cost benefit you need to have an increase in range between the 2 fuels of over 100km (based on a fuel consumption of 5.65L/100km also known as about 42 miles per gallon).
Which in suburbia is just not going to happen, so if you drive only in the city, the only reason to use the more premium fuels is to keep your engine clean.
An oddity that I observed, is that my last car ran better on certain brands of high octane fuel, and on at least 1 brand it caused hunting....
Great video. I've always started with lower octane fuel, and if the car didn't run right or had knocking/preignition issues, I'd move up to mid-grade. If that didn't make it run good, then you know you need premium fuel.
By that time, your engine will be too damaged to even accept premium fuel..
Natural selection at play! 😂
@@Otto45 Incorrect, I've owned many cars over 30+ years, I know what I'm talking about.
@@electronicsNmore not long enough then, you sold them and then next owner had to deal with your stuff, good job
@@emmanuellehuu8818 BS. One I kept 10 years, and the other is now 19. I know what I'm talking about.
@@electronicsNmore alright then
Hi. I have Class C Motor home based on Ford E450 which is V10. I felt a lot of difference between 87 octane VS 93 octane. Since it has 55 gal. tank which is hard to choose premium gas however it performed so well especially on hills that I got premium gas all the time on Utah trip for climbing all the national parks.
Reminds me of Mr. Regular's IS350 review.
"GAS IS GAS, IN GOES 87"
*knock knock knock*
"WHAT'S THAT SOUND??"
My GL1800 sees an incredible difference between hightest and regular!!! It had a terrible hiccup around 3000rpm, and inevitably did it coming out of a corner... which really screws things up ;-) I put hightest in it, and no more hiccups plus I went from 40 mpg to 45 mpg. Well worth it in my book :-) Excellent video, as usual Mr EE :-)
5% mpg improvement for 20% more expensive fuel
@Boom Kikker We have the same thing in the US with the ethanol being added to gasoline at approximately 10%, really makes it a pain when you go to use anything that has been sitting for a while, especially with carburetor engines, not really an issue with fuel injection.
@@dylanmansell5818 -just another reason for me to keep on with 93octane. 05 Toyota Sienna Limited 3.3 VVT-i.
Yep. My car gets better mpg on ethanol free, but it costs 70 cents per gallon more.
@@rowlandbuck2703 get bjs, costco gas.
Hey just want to say as a student of Mechanical Engineering I find your videos really entertaining and educational. I'd love to see one explaining Bluetec diesel. Keep up the good work!
91 octane in california when my gas cap says "use 93" checking in
I know that feel
The struggle is real, albeit unfortunately 😒
With that it may be due to altitude the closer you are to sea level the higher octane rating fuel they use where as the farther up from sea level you are there is less air so octane rating is reduced
christopher dimotsis and Idk why they still do it that way, that method went outdated as soon as the first computerized fuel injection system came out which compensates for that.
We have 93 octane in Texas
In Canada I know some drivers who told me they put regular in the high octane tank just to fill them. Not always but sometimes.
I'm interested to see how the results would turn out for older cars. I have a car from 2004 that recommends premium and I've always wondered how different it would be if I used regular.
Great video as always, I just run what the owner's manual recommends. But it is great to see actual data, so really with a larger engine, you will see some improvement. But, I don't think it's enough to justify the inflated price. Now, if your manual states to use premium, then you're kinda stuck with using it. The engineers that designed the engine, know what they are talking about. I have read stories about people damaging their engine by not using the recommended fuel and then the dealer wouldn't warranty it because they voided the warranty by using the wrong fuel. I learned long ago, you are better off establishing a good relationship with your dealers service department. Even though dealer servicing is higher, in the long run your car will last you much longer, and give you much better service. My wife and I have made friends with the local Nissan dealership, and when we go in for service, they always apply any coupons they have for the service they did. Sometimes they even throw in free stuff. So, in summary, if you plan on driving your car for longer than you financed it, take it to the dealer for service. If you trade cars like every 2 or 3 years, go to Walmart and have it serviced.
Best channel on YT. Requesting a similar video about motor oil differences.
It's worth noting that not all of these vehicles necessarily have an engine map that is dynamic in regards to it''s fuel supply, thus you'll see differences in power/fuel economy that are essentially negligible. Also worth noting is the fact that the A3 and the F150 only recommended premium fuel despite both certainly requiring premium for long term reliability (more audibly in the A3 as AAA found out).
This video was very interesting, I am diving into your channel and engineering in general. Loving it, you make a wonderful job :D
Happy to hear it, thanks for watching!
When I had my Boxster S (987.2), I needed to add fuel additive at every fill-up to avoid knock when California blend 91 octane.
I’m still going to use premium in my 2017 civic si
I've always ran premium in my cars, because I have always had mercedes or cadillac and don't want to go cheap on luxury style cars. I've mostly done it because in my mind, I think the gas would be cleaner and cause less carbon buildup in the cylinders.
Now, I have an Acura and maybe I'll try switching to normal gas for a few months. Thanks for the info.
My Volvo s90 requires premium, but is dual charged and actually needs the extra octane to keep the knocks at bay.
afrosheenix same thing with my s60
Lots of cars require premium. This video is for cars that recommend it.
I work at a Volvo dealership, and every car we have we put regular in and we don’t notice any differences.
Sure, it does all that, at the expense of power. Why have a car with any modicum of power, fill i with regular, only to have it stubble all over itself when you floor it?
And that's why I don't trust dealerships for *anything*
One of my cars is designed to use high octane fuel. Once, I forgot and accidentally put regular fuel in that car. It started to feel sluggish and was not performing as usual. I was almost ready to take it to the shop before I realized what I had done. I ended up adding some octane booster and it worked fine until the next fill up.
Judging by the comments, you may want to do a video on different types of octane ratings. ='D
I have! :) ua-cam.com/video/zf-OYXlhJis/v-deo.html
looking at your comment mate, you have no idea he already did, just like the ones you've been judging
izukenekuzi Triggered
izukenekuzi I didn't want to link his video on octane rating and wanted to leave it up to Jason to provide the information he would like to complement this video.
I used to have a saturn sky redline. It had gm's available lnf tune to bump it from 260 hp and torque to 290 hp and 340 tq. With the tune, you could not run anything below 91 octane or at a full throttle pull, especially in 4th gear when it loaded the engine fully at 23 psi of boost, you would drive straight into knock city. Granted thats from a 2 liter engine so its specific output was high for something designed in the mid 2000's as a regular street car. If you didn't run a cleaning solution through it every 8,000 miles or so it would do the same thing though that could have just been from carbon buildup due to poor fuel quality or the direct injection aspect of the engine. The interesting part about this was how much it effected the escalade. Knowing it can potentially make a difference for MDS equipped vehicles since they can remain in 4 cylinder mode more effectively may make running premium worth it, especially if driving conditions cause it to constantly switch on and off at it's usable threshold. The jeep i have now has the 5.7 with mds (recommended 89 octane running 87) and on a non level highway or with any headwind between 65 to 72 it will sometimes kick on and off regularly.
I always thought that if you have a higher compression ratio then you need 92 octane gas so the fuel and air mixture doesn't explode to early making the engine knock. That's how I always thought about it
Using Premium in my 2014 VW Passat 1.8TSI I see a significant difference in performance and economy. When I run regular it’s sluggish and the economy falls off. Of course here in GA we get the higher Octane Premium at 93. Good video but I’ll continue use Premium for as long as I have the VW.
Here's a good question:
Will a car that recommends premium fuel that has been filled up with premium all it's life last longer than if it was filled up with regular all it's life? Are there internal engine cleanliness/maintenance benefits to using premium?
Only way it'll make a difference is from reduced knocking or extra cleaning additives that are usually found in premium fuels. Octane on its own won't make any difference otherwise. Note that in the case of the Audi in this video it could very well make a difference as a lot of knocking was observed with the lower grade fuel.
Assuming that the car can adjust timing based on knock it shouldn't. However if anything were to go wrong and keep it from adjusting the knock would cause damage
IF it gets better fuel economy on premium then I would think because it's evidently burning more effectively that it would be burning cleaner as well but if there is no change in efficiency (mpg) then I don't think it would be burning any cleaner. At least that's my logic and my totally unprofessional opinion.
another very well put together video, love the clear explanations, feel like i learned something from it, took 13 minutes to watch instead of spending a lot more time reading the actual article, keep up the good work
My car runs on the souls of my vanquished enemies
Thank you, Conan the barbarian. 😅
I admire your level of intelligence and modesty. Enjoy your posts. Sadly, videos like this won’t go viral because numbers are crunching and some background knowledge coupled with with a quest for wisdom will be required. Thanks for your posts.
I need to run premium fuel because I have a turbocharged vehicle. Unfortunately, they charge almost a dollar more for it where I live. I'll probably do an E85 conversion in the spring, which only requires an upgraded fuel pump & flash tune. What happened to the days when premium was only 20 cents more? :/
come to the uk where a gallon of cheap fuel is $7
Yep, not too long ago it was a $0.10 difference, I'm guessing with the cost of oil going down they've adjusted the gap to partially compensate.
Sweet Geebus. Is everyone purchasing electric vehicles in the UK because of that?
Top 10 probably injectors too?
You need a flex fuel modulator too.
Just came back to watch this video again. I love it. Flies in the face of what most people will tell you to do.
Advertising sometimes implies that higher grade fuels have additional additives depending on the manufacturer. Is there any difference between low grade and premium within the same brand other than octane rating?
+Arlie yes, some will have more cleaning detergents in higher Octane fuels.
MrEE, Manufacturers have many reasons for recommending fuels, fluids, and maintenance routines for their vehicles. It isn't all about power. Perhaps a video on the other benefits/drawbacks of this particular subject would be in order. I know you'd love to discuss exhaust temperatures and catalyst life in relation to timing and octane... which could lead to conclusions about smog tests and warranty issues, etc. Looks like AAA even included the cat temp charts for you.
I use premium cause it makes me feel good...............in my pants.
His name is Mr. Regular, and he makes me BROWN..........in my pants.
I would imagine that *any* fuel dispensed into your pants would be very irritating to sensitive skin. But, maybe the manly scent could help attract the ladies. Either way, I hope you're a nonsmoker.
Jason, outstanding video my man! I have a question I hope you will answer for me. I have a 2017 Mustang GT/CS. The manual recommends 87 octane fuel. But I just noticed knocking the past couple of weeks. I've had the car for 5 years and never heard knocking. I guess I should use premium 93 octane now ? Thank you, Dan Reisker
Very informative, really enjoyed this one.
Congratulations! Another professional analysis of yours. You are speaking as a good lecturer. I know what I'm saying - I'm university professor in Poland. Good luck!
What do you think about shell vpower 95 octhane gasoline?
My 2000 (purchased new) Dawoo Nubira wagon recommended unleaded when new. The mileage initially was 26-27 hwy and 18 in town. In experimentation i began recording results that i got using various Brands of fuel. No particular difference was noted other than one brand whose reg. unleaded with high amount of detergent additives and a min. of one point octane higher seemed to increase mileage by 2-4 miles per gallon and add power (to the delight of a certain lead foot female with more tickets than me with whom i share driving duties).
After the first year i asked our mechanic to check if there was anything he could do to increase mileage..he said everything was 👌 perfect. As an experiment i advanced timing by 3 deg but the computer cancelled the effect out so i reset it. Instead i began using high octane fuel from that same maker. Today after 140,000 miles, very faithful routine maint, and zero engine issues and only one tune up needed we regularly get 33 mpg hwy and 22 city as long as we drive 60-64 / 25-40 resp. It burns no oil..yet.. all i can say is to do the maint that you would do on a ‘65 Chevy rather than the ‘every 12,000’ miles recommended and a newer car will last forever. Our 18 year old Nubira still drives and hums like new, has good power and has never needed any expensive repairs! We plan to keep it until 300,000 miles since it still looks like new!
This video completely confirms my using and recommending premium fuel. Another added benefit are the additives that most premium fuels use which helps to keep clean injectors and many other engine responses, in terms of power and engine smoothness, which could and should help the engine's longevity. The bit more expense using premium over regular octane is well worth the extra cost, in my experience and opinion.
I dont think premium is worth it. If you sum the difference compared to simple regular fuel, it can be a lot of money after a hundred thousand km. It also depends of the complexity and cost of the parts for the engine. One thing is injectors for a regular atmospheric car, other are high pressure fuel injectors in direct injection systems; in the later I would definitely run premium of a reputable brand because the parts cost is much more expensive than the sum of the difference of the fuel over the life expectancy of the vehicle.
Additives are the same across the board for top tier certified fuels, only difference is octane rating.
I don't think so, Top Tier fuels are certified as Top Tier, but the additives can vary by manufacturer. Even the refineries will put in different additives to fuels going to different brand stations to satisfy that brand's specs. There's also debate on the effectiveness of such additives in GDI engines, where the fuel is sprayed directly into the combustion chamber instead of into the intake runners and on top of the intake valves. For the latter I think a Top Tier fuel would work better to keep things clean. But, I still just put cheap(er) Kroger 93 octane into my Integra GSR. Been using that for 16 years with 362K miles on the original engine (and original injectors and fuel system) so I think it's doing okay.
Patrick94GSR - when I said the same across the board I should have qualified it by saying the additives from the regular to the premium are the same with each manufacturer having their own blend, ie whatever shell uses in their premium is the same as their regular, same with Chevron etc. They makers have their own blends and their blends have to be universal across their octane ratings to be top tier certified. As for top tier certification, that is something the manufacturer pays for so they can advertise it, doesn't mean they are any better, it just means there is a place that tests it and then stamps it that way (just like THX certification, look it up, it is interesting). I too use Kroger lowest octane because not only do I take advantage of the Kroger rewards, but my car runs the best on it. Thanks for helping me clarify my original post.
Mr Bob there is here. Here for the same octane rating, you have simple aka pure and premium aditivated like BP Ultimate.
Thank you so much for this video. I have been hunting around for a while to find a comprobile video that ACTUALLY answered my question of "should i say with 95 or try 98?" (my country uses RON so 87? vs 91 by US standards i think) and all i found was opinions. Thank you for actually using decent and easy to understand data and explaining it so well
91 vs 93 US standards is the same as 95 vs 98 RON, typically.
WHY no memtion of compression ratio ??? It MATTERS
On modern VVT engines the mechanical compression ratio is considerably affected by valve timing and overlap.
I had an old car that knocked going uphill, and high-test gasoline fixed that problem. Then I found that plus grade worked just as well. It only knocked on regular.
Lol Escalade with a 6.2L V8 getting better gas milage than the F150 Ecoboost V6. Well done Ford
Matthew Tyler that F-150 can also tow 13,000 lbs. The tune is different to do a different job. The Escalade is more for passengers. It’s not made to pull that much so it can be tuned for better mpgs.
Is because the escalade its using only 4 cyl mode
All turbo engines will run richer when the boost is up.
@@RedIIIXGaming Well the 2wd Caddy is good for only 8300 lbs trailer. Due to the added overall empty laden weight.
Flat grade, no acceleration, unloaded. Sure.
Hello EE. Big fan of your work :)
I live in Poland(Europe) and have I also used in the past premium vs standard fuel and didn't see a difference.
Now i have Honda Accord VII 2,4 liters K24A3 with have static CR 10.5:1.
It is premium fuel recomended, but not required. I run it on LPG.
On sequencial LPG instalation cold engine is running on fuel till temperature of engine achives certian level(about 40 degrees C). After that it switches to LPG.
To the point. I run it on Shell V-Power 100+ Octane(Euro rating ofc.)
I do it because I noticed that my engine achives working temperature faster(even when LPG is off) and my thinking is because it more efficient(more power with the same ammount of fuel as you pointed in the middle of the board)
Just wanted to share my empirical expiriance :)
FYI. LPG is 103 octane Euro rating - mayby you want to do video on that
87 minimum 93 recommended checking in
Interesting video. I have an Opel Mokka, Buick Encore to you in the states, with the 1.4T motor and it was interesting to see that it lost power using higher octane fuel. Just picked up the vehicle and I have always trained myself to use the higher octane when it comes to gasoline motors. Last few years has seen my driving diesels, so it was interesting getting back into a gasoline motor. Torque is flipped and it drives me nuts.
Great video as always. Keep up the great work!!
The results were presented in a misleading way. The reason the big engines had higher %diff for fuel economy is because they have lower fuel economy. A 1 mpg improvement on a car that gets 10 mpg is 10% better, but if a 40 mpg car gets a 1 mpg improvement it is only 2.5% better.
This is why when talking about fuel efficiency it makes more sense to use the perspective of fuel consumption not fuel economy, i.e. use units of [gallon/mile, g/km, l/100km, etc] instead of miles per gallon. Its the same reason you do thermodynamic calculations using absolute temperature [K] instead of relative temperature [deg C, deg F]
I have questions about the test methodology as well. Some of the engines had almost no spark advance for the high octane fuel, so did AAA properly prep the vehicles so the ECU updated fuel trims? If they didn't how was the car supposed to know it could spark advance without knock?
Well spotted. Not sure if it was done intentionally but it is relevant. Also the numbers didn't reflect the improvement in the power and torque curves of the MX5 across the entire range. Still it does not explain the performance loss or the audible audi knocking O_o
Maddie Shan You are correct. It would be cool if someone regenerate the charts with gallons/mile or L/km.
German engineering is always a mystery.
I don't understand what you mean. If you're trying to figure out if it's worth it to buy premium gas, of course you want to compare your efficiency gain % with extra cost %. How is that misleading?
I'm not sure I understand your argument about fuel consumption vs fuel economy. One is just the inverse of the other, so when you describe the differences in % you still have the same problem. So in your example the car with poor efficiency would see it's consumption decrease by 10%, and the other car would see it decrease by 2.5%. Anyway, it's not really a problem because you want to describe the changes as percentages.
It's not at all the same issue as you have when you use celsius/fahrenheit instead of kelvin. Celsius and Fahrenheit have arbitrary 0 values, that's why it doesn't make sense to use them in thermodynamic equations.
In my NC I feel the difference on full throttle.
In my Mazda 3 Skyactive, I feel a hick, and logging timing to the laptop, you really see a step in ignition timing on RON 95.
Use RON 98 (93) in both cars now.
My Mazda test car already uses the maximum ignition advance setting with the use of my prototype.
You sick?
You sound sick. Get well soon.
Thanks. Sick indeed. :/ Doesn't stop me from a little whiteboard action!
Engineering Explained get well soon
So nice of you.
Great review. A couple of points may have some merit. 1 intake airflow using premium at higher rpm uses less o2 vs regular this may also contribute to increased gains. 2nd my veloster is listed as regular however gains are noticed , without premium minor pulsing is experienced, I suspect hyundai set ecu to accept higher octane. Would have been nice to see the test on a gm ls3 that has two mappings with stock ecu
drink15 .L298))
It's always been the case that different engines designs respond better than others to higher octane and performance tuning. Since the introduction of fuel injection and the addition of knock sensors this has become less transparent to owners and mechanics hence the misinformation, over simplifications and generalisations that now abound. It great to see a study like this which puts the spotlight onto the manufacturers and how much their engine design can benefit from optimal conditions (fuel).
I run Mobil 1 synthetic oil and Mobil 98 RON fuel in my Merc CLK320 to give it the best chance of performance, efficiency and reliability. Very happy with the result.
Great video keep up the good work👍
I would like to add something. Compression ratio also play a huge part in using octane diff.
Like Mazda skyativ engines. It is recommended to use 95(Asia) but there is a huge diff when using premium(vpower)
Turbo charged also have huge diff when using premium fuels
If your compression ratio is low like SSS(12:1), there isnt any huge diff. But like I was saying, for Mazda skyactiv models(14:1) there is a huge benefit.
You can try.
Can you do a video on octane booster juice? I would love to see how much various engines can benefit from like 108. From this video it seems a huge NA engine would be most likely to benefit. Do turbo racing engines really benefit from high octane then?
turbo engines greatly benefit because then you can turn the boost up! lol
There is only one “Octane Booster” product I know of (and have personally used), which actually works.
It’s called *“Race Gas”* (unoriginally enough); and when mixed with 93AKI, can make up to 105 octane at full concentration. All *UNLEADED,* of course.
*EDIT:* Pretty much any “108” you speak of, will contain Lead and thus, is not suitable for roadgoing / emissions-controlled engines.
The *Race Gas* product is rather expensive to boot, and not something most people are likely to run on a daily basis. Much like actual, purpose-crafted racing fuels.
bro, the 510 connection is all you need to hit some large clouds. I might be on the wrong channel.
wow, fascinating video Jason, i really appreciate the work...I have a 2004 tacoma with a 2.4l and toyota recommends premium to help reduce carbon buildup so i use 91 and I can still hear a slight ping when pushing the motor hard as if the computer is giving it as much advance as it will take but my wifes 2011 camry with a 2.5 runs great on regular...I have to admit I have never read her owners manual but the one or two times I ran high test it didnt seem to make any difference.
Thats why i go to costco gas
I've made the mistake of using CostCo has and almost ruined my damned car! 76 Gas for my car ONLY!!
MotorHead Tech is it good gas
Great video, I have a 2008 mx5 and I think that the reason why the numbers didn't change is because premium fuel is manufacturer recommended or required. Besides the owners manual saying it, there's also the gas door which says premium fuel. This is if you were taking manufacturers mpg rating into consideration. But very much makes sense to me now. Thanks Ohio!
So how does the engine recognize if its high octane or lower octane fuel?
Ankit Sharma hears for knock
Ankit Sharma knock sensors determine if it is knocking and how much to adjust timing if it is
with oxygen sensor on the exhaust line (lambda sensor)
Can't measure it directly (although that would be cool) - ECU's will advance ignition to the point where it starts seeing knock, then backs it to a safe level. Thankfully, modern knock sensors & detection algorithms are very good.
wrong
With proper ECU programming (sort of chip tuning) you actually can get a significant improvement in power by using fuel with higher octane rating.
For example my Audi A4 B7 1.8T had 163hp and 225Nm as stock with 95E octane fuel (I'm using the European RON-scale). With stage 1 program numbers increased to 185hp and 300Nm with 95E and 198hp and 320Nm with 98E fuel. 6,6% differnce in power by increasing octane number. Now my car was re-programmed for E85 fuel (bioethanol) which is equivalent for 105-106 octane fuel. Car produced 224hp power and 387Nm in torque.
27,2% increase in power in total by using fuel with higher octane rating and programming the ECU to match the fuel.
Car has been dyno tested with each fuel with the same dyno. Only mechanical upgrade are the injectors which has been replaced to match the amount of fuel injection with E85 (avg. 20-25% higher fuel consumption due to smaller energy content).
Do you guys have difference in ethanol percentages in "regular" vs. "premium"? If so, there might be some other long term issues with using cheaper fuels.
Premium (at least where i live) doesnt contain ethanol
I've tested both regular and premium where I live with a cheap ethanol test kit and they were always 10% ethanol. The only change from that are special fuels we have here. One is E15 with 15% ethanol sold at only a handful of stations and we have 1 station that sells E85 which is 85% ethanol. That blend is pretty rare here though, like I said only one station. This is in Dallas, TX USA.
Currently where I live, in some places premium fuel is cheaper, because of a price spike of regular (regular is 2.07 NZD per litre) so we are paying just under US 5.50 per gallon of regular, but premium was 2.05 NZD/L where I filled up, so it was 5.44 USD per gallon.
If only they stopped marking up the price of premium gas by 30%...
Yeah, I agree with you there, doesn't make sense that the gap has increased so much, without necessarily a larger demand.
Some gas stations are worse than others. If I leave work and fill up in the rich folk area, I'm paying a high price for premium. Get closer to home and premium can be $.40 cheaper.
depends on where you live! I live in Mid Missouri and our Premium price mark is $0.40 higher than the regular price. I drive a hybrid and apperently they love Premium fuel! I get about 18% MPG improvement when using Premium, so unless the gas market suddenly crashes and regular goes down to $1, it will be more benificual for me to stick with Premium!
Paying .60 cent more per gallon.. in my minivan😫 -😂🍻
I think it depends on the average ambient temperature, compression ratio of the engine and cylinder shape (is it under or over square), type of injection (Port or Direct) and if it has forced induction or not and materials used. And that is all dictated by the purpose of the vehicle.
Bottom line is how much heat the engine can handle is what dictates the type of fuel used. I mean, like the Jeep if running at X boost on regular fuel will take X microsecond to ignite fully but with premium fuel that has a higher knock rating, will take X+ microseconds to burn therefore energy released by X amount of fuel is not utilized like when using regular fuel.
However, if the tolerances are too small, premium fuel requirements is there to protect the engine and not to produce more power. Power is a by product though of the smaller tolerances so it is tricky.
What I do is I use or 98 octane premium fuels in long drives or if I expect to rev over 3000RPM but if I know I will be driving only in the city, then I will just use 95 octane. We are still have 90+ F or 32+C days here considering it's December already.
@EE i'm curious about the effect of premium fuel for regular japanese cars, that don't require premium fuel
Good info here Jason ! I use premium a bit simply because I don't burn through a tank of fuel in a month. With fuel sitting int he tank for 30+ days and the Midwest having this ethanol stuff, I didn't want to take chances of the water separation issue. Maybe an idea for a video ?
Can you put mid-grade gas on a car that requires 87 octane im curious?
yup you sure can. my 2016 chevy colorado with a 3.6 requires 87. but now with just over 70k miles with 87 the engine spark knocks ( rattles ) at low rpm and a light load. slow accel from a red light. running mid or high grade stops this annoyance. but yea it will not hurt your engine to run higher octane.... just your wallet due to its price difference.
My evidence is anecdotal, but works for our vehicles. 13 Altima 2.5. Recommends 87, at our altitude of use (between 2000 and 8000 ft above sea level, primarily 5100 to 5400 ft), every dealer for our car stated 85 will work just fine. Use a Top Tier gas, preferred brand has only 85 or 91. 10 tanks of 85; felt like a typical balanced shaft 4 banger; shakes at hot load idle (stop, foot on brake, a/c on) but otherwise felt.......normal. Then, 10 tanks of 91 from same station. Wife noticed hot load idle felt smoother to her; I noticed the steering wheel buzzed less. Perception was run up the passes more at ease. Fuel economy went up about 8% (may be attributed to continued engine break in). After a few cross country runs (summer with passes over 9500 ft, including Eisenhower, Vail and Monarch in Colorado) with zero problems, all the power wanted for getting up the passes, tried 85 again, same brand. Within half of a tank, wife asked what I had messed up in her car; went back to 91, and 92,000 miles later, very satisfied and will never put less than 91 in that particular vehicle. Whereas 2008 Sierra with Vortec 4.3......it couldn't care less if it is 85 or 91; did the same type (with fewer tanks) experiment. To me, each vehicle, although the same model and engine, is an individual and results can vary.
What about my G37 that says premium unleaded REQUIRED on the gas cap?
REQUIRED... REQUIRED... Its a VQ engine
MRios1128 I own its sister car a 370Z and I always put premium in her.
gea g37 are pretty high compression cars and if it says premium required then deff deff put it in youl also feel a power loss in the upper rpms with regular.
Your concern is not fuel efficiency it is engine reliability
Change your gas cap.
Nice summary of this study, which does a good service to those who drive a car with merely a recommendation for premium fuel, as opposed to a strict requirement for premium. I'm glad to see that you emphasized this point for the benefit of those who missed it. I do have some questions about the 25 percent price difference between regular and premium, as I've only observed differences of less than ten percent in my region.
So less than 5% improvement in performance for a 25% higher priced fuel, not very worth it
ITUBE your honda doesn't need it im sure
% increase in performance varies wildly.
The difference between 89oct and 93oct on a midlevel boosted car like a m3 would be 50 or even 75hp even stock, that's a big difference
Shawn Jones scion tc*
5% more power is notable and is cheap for a mod if you bought a car that was meant to go fast and one does drive fast.
Best used in cars with higher compression, be it dynamic or static, along with more agressive cam profiles and higher flowing heads. The whole purpose is to mitigate pre-detonation. Whole reason people run alcohol in dragsters, as well as the cooling aspect of how much of it gets pumped into the cylinder
Would be good to see one of these comparisons where a performance build car (drag, drift, time attack) gets tuned on the different fuels and seeing how much difference it makes, just using the stock computer too vary the timing etc won’t get as much gain as a tuner with a good ECU
I seek out pumps that have 93 octane for my Si. Because when you've got 11:1 compression.....yeah.
Logλn L Where do you find that?
StrangeClouds Australia. ...we got 98 and some pumps got 100 octane but ur paying over $1.60 ltr for it. .!
Si has to use premium
Awesome video. Can’t believe I only saw this now. My 2016 crosstrek says in the manual to use RON 90 minimum. The filler cap has a sticker recommending RON 95. In the long run is it worth having to pay extra for what the 95 fuel offers over the 91 fuel?