I like how you provided facts and real test results in your video instead of just talking about it like everyone else. Great video! I have a better understanding of this now.
@@mohamedgaaloul2753 knock sensor doesn't necessarily mean per cylinder adjustment. Lot's of older EFI cars had just one knock sensor and would not even immediately know which bank on a V engine is knocking until it made adjustments to STFT and observe if it helped or not. With port injection, and sometimes batch fire during startup or even steady state on some older EFI ECU you don't always even know for sure which injector to adjust until several cycles of making adjustments and observing plant response.
this is my take on octane: With high octane fuel, it is refined to slow down the combustion speed and drag it out over a longer period of time. So, it ends up being a cooler, but longer burn than low octane. Because of that, timing can be advanced a bit more. My experience shows that only under heavy acceleration, or load, the engine shows it's true colors. As most of us know, all modern gas auto engines have a computer with knock sensors that "listen" for knocking (early combustion) and adjust the timing dynamically to stop it. So, with that being said, IMO, if you do a "butt dyno" making runs using 87 oct and again using 100 oct racing fuel, ya....you may notice a bit more punch with your daily driver. Worth it? Naa. That's my own opinion on the topic.
your videos are usually spot-on. the truth of the matter is higher octane fuel has less BTU or chemical energy than 87 octane. octane is a function of compression ratio and actually requires more ignition timing because the higher the octane the slower the burn. this subject is way more complicated then even I can get into in a comment section TH-cam video
It's also interesting to note that lower octane fuel ignites quicker which can give you better throttle response and improved economy. Some cars feel sluggish on high octane, my Ecotec 2.0T feels deluxe on 91 but it still goes like hell on 87. No knock, I just hear the turbo. I'll give it 91/93/94 for the mountains but around town it seems 87 is just fine.
I notice the difference between Sunoco high octane and the Shell V-Power Nitro+ in my Porsche 718 Cayman S PDK. It's got the extra edge as a result of the 99 RON. With a 3.6 second 0-60 mph time, it can be difficult to perceive the difference, but it is there.
All of this is dependent on the timing of the cam shaft and ignition with the position of the piston. A car meant for unleaded 87 octane can run better with 87 octane rather than 93 octane, if the timing was maximized for 87 octane.
Now this is what I've been looking for!! Yes I'm that person asked you on octane and power on FB Jason... Thank you very much as always!! so Higher octane can possible result with more power (of course this doesn't apply to all cars)
Finally a demonstration that show how that actually works out. I always assumed that if your engine doesn't knock on the lower octane fuel then you wouldn't actually see any anti-knock benefit with going with the higher octane.
Yea, that's not true with the newer cars, since they just pull timing to prevent the knock. My supercharged Grand Prix is that way. Run regular unleaded all you want, runs fine. Run premium in it, the computer throws the timing back in and you're up about 30 HP.
I used Shell V-Power 93 Octane for my road trip to Boston on the weekend of New Years. The vehicle is a 2014 Subaru Forester 2.5 Touring with EyeSight. The engine does have direct injection, although required octane is 87. At cold temperatures, 87 lowers fuel economy when I drove to Albany last year to visit my sister at the time. Shell V-Power 91 or 93 has 5 times more additives than their 87 octane, and if you have a direct injection engine, requiring regular or premium gasoline, use Shell V-Power once every 5,000 miles to remove and prevent carbon build-up on injectors and in some engines, intake valves.
+Tim Joseph You're not going to clean your intake valves with fuel on a direct injection engine no matter the grade or how many detergents it contains. Direct injection combined with EGR is WHY you see heavy buildup in the intakes; no fuel in your intake to do the cleaning. Carburetors and single point fuel injection systems had no real issues with carbon buildup because everything was constantly soaked in fuel and cleaned.
I own a 2001 mustang and I’ve been using 83 for so long so I decided to switch to plus gas, I actually noticed a bit more power in acceleration. Then I tried premium in it, and noticed a tad bit more power and man I’m liking it, cause the V6 isn’t too fast in the first place but it makes it seem a lot more powerful.
It depends on what your car is tuned for as you said, you might not want the timing too fast and the piston still be on it's way up. That would creat higher pressure but would give you much less power.
All car are different, from manufacturer to manufacturer, turbo to NA, and country to country. Shell chose a car that can cope with the requirements of the test. So what? Premium fuel has benefits for hp and as a result, economy. That's a fact. All engineers know this. However, some cars are programmed to give those benefits and some are not. I don't understand why, but this seems to me more common in the American and Canadian cars than elsewhere.
Pavel Kovalkov nope this is 1.4 or 2.0 engine such as Gti so in Europe designed to run with 95ron but could detune for 93ron. Whereas in US, it is usually speccd for 93ron and can be tuned to 95ron if used
+Nick Palaroan Hondas sold in NZ from '96 on used knock sensors to detect octane and automatically adjust giving a hp boost as octane rating rose. This is what we service technicians were taught by Honda NZ and the info came straight from Honda Japan. The PGM-FI was fast enough to adjust for a different octane rating every stroke. This technology is everywhere now but it seems that some manufacturers still cut costs by optimising for low octane only. The sort of person who thinks a Corolla is worth buying wouldn't be able to tell the difference anyway.
Steven Farrington The problem with using a fuel with a higher octane rating, than specified by the mfg, is that the car cannot detect higher octane at all. The sensors detect knock (ostensibly from too-low an octane) and adjust the timing until the knock goes away. If the engine is rated for 91 octane and there is no knock from that gas, then adding 93 will do nothing. The car can't tell one from the other. In fact, using a higher octane than specified can actually reduce performance and increase pollution.
You should do this video again but with a n/a economy car. There is so many people wasting money putting race gas in their "performance Civics" around where I live and I'm wondering if higher octane gas even makes a difference on those cars. I'm guessing the answer is no considering those cars weren't tuned for anything higher than 87 octane, unlike the turbocharged golf in this video.
Lawrence Timme In the UK, petrol is rated using the RON standard, us Americans have our fuel rated using the AKI standard. That's why the octane numbers differ so much.
You can't necessarily hear uncontrolled combustion events (aka, 'pre-ignition', or 'knock') from inside your car. It actually has to be pretty severe to be audible. So which fuel to use was a much more critical decision, in the days before EFI and knock sensors. Back then, for the vast majority of applications, the object was simply to protect the engine. Carburetor and ignition tuning were conservative, and more stable 'high-test' fuel provided additional insurance. There was a laborious process of 'spark plug reading', followed by ignition and carburetor tuning, used in racing to extract maximum performance. But it was only good for the specific current ambient conditions (barometric pressure, temperature, humidity). Not very practical or useful in a daily driven car. Once self-adjusting engine management and knock sensors came along, an engine could take advantage of premium fuel to produce more power safely. Given what Shell V-Power costs, the question is whether a slight power increase justifies the expense. Bottled injector cleaner is a cheaper way to get better fuel system cleaning. So, are you running around at max throttle and load on the street? Or racing your car professionally? Probably not. It's your money...
Thank you for this video, I was trying to explain this to my friend but I haven't been able to really explain it to him well (I've only just started engineering classes). I'll be showing this to him asap!
It's like gun pouder you want the burn to not stop till the shot leaves the barrel. If it does the bullet has barrel drag and slows down. Same as high or low octane fuels .
Love your videos, I learn a lot. One recommendation I have is increase the lighting in the room where you're filming. You can bounce a light off the ceiling or add a soft box with bulbs.
I’ve always run 93 octane fuel and have never had any major mechanical issues in my vehicles. It sparks faster and runs more efficient especially in high performance cars that’s one thing I’ve never understood when people use 87 octane in a powerful v8 especially for racing just because they want to save 5 bucks at the pump for me it’s totally worth it and the science backs it up.
Well, actually, the higher the octane rating of the fuel, the HARDER that fuel is to ignite & the MORE heat is required to ignite it! They also burn slower than lower octane fuels as well...
I did a test on a long drive across Pennsylvania where I used 87 octane on the way out and 89 octane on the way back. Not surprisingly, the 89 octane gave me better mileage. The next step was to compare the increase in mileage to the increased price of the 89 octane fuel. The result? Although I got better mileage with 89 octane fuel, it actually cost me more per mile to run the car. So...I'm actually better off running the 87 octane and getting less MPG. If I were doing a Track Day, 89. Day to day commuting...87.
Dope. I wish this tech had been around back when I argued basic chemistry and physics with my auto shop teacher (turns out I was right). Of course, at the time, we didn't have advanced EFI systems with on-the-fly advance and knock sensors on cars we could actually work on in the shop.
My 2018 Mazda CX-9 takes off when using Shell V power. It can alter ignition timing. Though premium isn’t required, regular 87 gives 227hp, with 93 giving 250.
My 2017 Volkswagon Gti will get a slight bump in power with the high octane but as shown in the video will adjust and run fine on regular gas as well with almost un-noticible performance. The cost of the high octane is not worth the benefit so I don't use it on a regular basis. I fuel up with high octane a few times a year because it has fuel additives that are beneficial to cleaning the injectors that the regular fuel don't have.
This is only one part of the explosion. The higher your compression in the car, the faster it will detonate. Some cars don't produce the heat and pressure required to run (explode/combust/tear bonds) of higher octane (more carbon bonds) fuel.
Yes, but let's use 103 octane on the same car in an Alaskan winter and see what the conclusion is. The point I'm trying to make is that people have unfortunately concluded that higher octane means more power, and that is far from correct. You need the right octane for the right car and condition. Track temperatures can be significantly higher than ambient, and driving behind another car can increase engine temperature from lack of cooling. True wind speed and cooling systems, engine load, compression, spark (plugs), and radiant heat all play a role in how a car detonates. I still see guys putting premium fuel in cars that can take 87 while commuting in them in cold winter conditions. Then they wonder why their engine is knocking. In many cases, they are wasting money and getting less performance.
+bon vivant My car have's 10.5@1 compression and tempetures here in Puerto Rico are about 91 to 97 were I live. I've tried with gasolines from 91 oct. to 93 and still knock! it's a 2012 lancer gts 2.4l My question is, can it be a lean problem? The car is 100% stock!! and have's 30,000 miles on it. Spark plugs are completly yellowish brown.
Sorry to hear that Luis. Dark plugs are usually from carbon buildup from fuel that isn't burning completely. Take it to the shop and have them tune it. I wish you luck with this.
But to have a difference, the engine must be designed to use higher octane gasoline, right? If the engine already reaches it's best performance with regular gasoline, there won't be any difference in pressure by using a higher octane gasoline.
uh, not necessarily... there are many factors there... compression ratio, ignition timing, fuel mixture, air pressure/density/temperature.... octane is just part of the story... there are other additives in fuels that can also be a factor... not all fuels are created equal, but the standards in the US make them pretty darn close. etc... etc... you almost have to take it by a case by case basis depending on what engine you have.
Shell determined that Shell V power performs better than regular old Shell in a Shell V power optimized car on a dyno. Ignoring the conflict of interest, 3% performance boost doesn't seem worth an extra $5 a tank (or more) IMHO. Great video, I was just finding a bit of humor btw
Its all sponsored by shell, so of course they will want you to buy the most expensive fuel. Run the fuel your manual recommends as there is no real gain in running the higher octane.
I am not a shill but honestly shell fuel and shell/pennzoil oil is really the best of the best ... Pretty much every high performance manufacturer recommends shell fuel and ferrari only uses shell/pennzoil oil..
I ONLY run Shell in my high compression snow blower as per 2 mechanics advice. The performance with the premium gas is miles away from the other levels. My car gets it's best MPG on shell basic and I run Marvel Mystery oil.....cheap walmart 4 OZS in gas tank 8 OZS in oil for cleaning and lubrication.l and get 40 % less friction and 40 % higher MPG at 60 mph for the last 2 years.
Charley Bomps I ONLY run Shell in my high compression snow blower as per 2 mechanics advice. The performance with the premium gas is miles away from the other levels. My car gets it's best MPG on shell basic and I run Marvel Mystery oil.....cheap walmart 4 OZS in gas tank 8 OZS in oil for cleaning and lubrication.l and get 40 % less friction and 40 % higher MPG at 60 mph for the last 2 years. Read moreShow less
its more than just ignition timing. It's also about the turbo boost. regular fuel will decrease the boost pressure which reduces effective compression ratio, which reduces knock, and obviously lower hp.
Well put young man! Personally I'm more interested in using the ESSO synergy +99 as it has no ethanol, as the ethanol is reaking havoc amongst older petrol engined vehicles, destroying 'o' rings cork seals etc. I'm not knocking the other brands though. No pun intended.
Without knowing all the details; higher octane fuel makes my bikes accelerate faster and gives me a higher top speed. I have tested this in Germany where I can actually reach top speed legally.
Great! Thank you! I have two other engineering questions for you that im sure you will be able to answer for me, but they require a video to ask it, once I figure out how to do that I will send it your way :)
I have a 4 litre turbocharged 6cyl engine running liquid LPG injection. It runs way better on LPG than even premium because LPG is up to 110 octane so the tune winds up the advance. I use premium gas in the petrol tank because it's only used for a brief period after start and Premium has more detergents to last longer and be cleaner. I can only thrash my car on LPG though as it pings on anything else.
Hi, im writing you from France. First of all, thank you very much for the quality of your videos and explanations. I was wondering if you plan to do a video about e85, flex fuel and stock vehicles using this type of gas without any kit or whatsoever having their car working fine thanks to the ECU and injection stock tolerance. It is extremely difficult to know whether it is dangerous or not for the engine, no one seem to have a proper answer about it. Some seem to use e85 on a daily basis for years without encountering any problems, though others explain that it might harm the engine... It would be nice to have your view on the question ! Anyways keep up with the good content :)
Stock timing maps of regular cars usually won't allow any adventage of using high octane fuel. To have any power gain, you would need to tune timing maps first.
andrew aswert Agreed as they have to accommodate all fuel maps, but some systems (modern ones) are capable of altering timing based on fuel used (as demonstrated).
Very informative Video. Well done. It would be even more interesting if You would have tested the real benefits from higher octane fuel when driving a normal car as this Golf 6 on the road
We can already tell you, it probably runs better and gets slightly better mileage. This is a general constant, however you may not notice gains in your particular car, especially if the compression ratio isn’t high enough to take advantage of the higher octane fuel.
my 2002 sentra spec v says to run 91, I noticed running lower grade the knock. 91 it sounded better and got better mpg. Also most had modified the knock sensor to let it become LESS sensitive.
I'm not an engineer, but I do understand the mechanics of how this works. All the posters comments are dead on! I do have a problem with two cylinders running on one gas and the other on a different gas. They should have, as mentioned earlier, ran a test on all 4 cylinders on one type of gas, then on the other higher octane rated gas, and gone from there. As far as timing goes, they should have not done a pressure test on 2 vs 2, as the engine pistons are connected and even one cylinder affects the other three. I see the point here, but believe it is psuedo-science to promote a fuel that could have been tested much more EFFICIENTLY ON A DYNO.... lol. HIGHER PRESSURES COULD BE FROM KNOCK, SO WHO KNOWS... TIMING IS IRRELEVANT AS THE PISTONS ARE CONNECTED AND "play" off of each other......
Everyone tells me I waste money using the higher octane, they say it makes no difference. I have a big mtn just outside of town, if I set cruse control at 40 the truck slows down and shifts which speeds it up then it shifts again. It does this shifting back and forth no matter what I set cruse at. When I use higher octane it gives just one steady pull up the whole mtn. I also get more miles per gallon, not a lot but some. At the end of the day, even with greater MPH I'm still paying more for the higher octane. I'll pay it for the better performance and better mileage. I have tore down a couple motor's after using the high octane for a number of years and the inside of motor is clean, hardly any carbon build up or varnishing. Add up the extra mileage, better performance and a much cleaner motor and it's worth the extra money
I going to explain in this way, Octane is basically the autoignition temperature, and because air it heats when you pump energy to compress, algo elevates the autoignition point. If you will go to get an car in which you wan't to put let's say, a 3 bar turbocharger (45 psi) you wan't a fuel good enough to take the pressure without knocking. But if you don't your engine possibly will not burn ALL OF THE FUEL, and you gonna get less power, this is a problem that i get when i decided to conver my old engine to natural gas, with a 120 octane number. Isn't really octane what gives you more power, is the advancement of the plug and the higher pressures you can work on it what gives a little bit more power, if you got an old mustang v8 N/A with a 8.5 compression ratio you don't really need high octane fuel, because you will possibly lost power.
H Mack I don't have any preference or recommendation,I've just had bad experience with V power.I filled my gas tank with Vpower once and I had a HUGE loss in power,I had to use full throttle going up even the smallest hills and could barely accelerate enough to keep up with traffic ,whereas I can normally pass all traffic as my car is much more powerful than most cars where I live.
agreed, they should test those fuels on a car that doesnt need it like a basic bare bones economy car designed for 87 "regular" to show whether or not youre wasting money on "premium".
It would be really cool if you did a bit on octane boosters. i.e. do they boost octane to the extent that they claim they do. I live in SF California and it's a decent pilgrimage to get 93 octane fuel. i have to drive like 30 min to a station that has 100 octane racing fuel and mix it with 91. I'm not looking to see if they give performance gains or anything like that, just octane ratings.
Shell gas is objectively speaking the best. Oh, Chevron, Sunoco, Mobil and Gulf would like to say different, but first they have to make videos, or no one will tout their claims because no claims exist. Shell is also superior in beating the competition to the punch.
I think you might be confusing a few people that won't go back and watch the octane video because they feel they lernt enough. To fill in the gap.. Octane has a direct relationship with compression ratio and also to how fast it burns. You WILL get less power and reduced MPG if you put high octane fuel into your car that recommends 87 octane fuel, but if your system is designed to run 91 octane and you put 87 then it will choke the system reducing the air intake to prevent knock and of course reducing power and mileage. But if you car runs better with higher octane even though it recommends 87... you need repairs, usually a good tuneup and fixing intake leaks.
Higher octane ALLOWS more advanced timing which makes more power, but the car has to be capable of adjusting for it. Older cars rated for 87 octane will not advance their timing and will not make more power if you fill up with 93. Newer turbo cars or custom tuned cars most definitely will advance their timing and make more power on 93 octane. It depends on the car. Mazda Skyactiv is a good example. It will adjust timing and power output based on what you fill up with. 227HP on 87 Octane, and 250HP on 93 Octane.
Why does everyone assume this is telling you to run premium in your 89 Tercel? This is purely to show the uninformed what happens when you run lower than the manufacturer recommended rating. If you want to run higher than the recommended, do it for the detergent packages. Because the car won't be able to take advantage of the extra octane rating.
So from what I understand from this series of videos, there is no harm in putting a higher octane fuel in your car than what its rated for. But if you put a lower octane fuel in then it has a chance to prematurely ignite and cause knock. Is that right? Just wondering because everyone I talk to says that knock can be cause by too high of an octane rating as well.
Forgetting something vary important here...sure it prevents knock, but it also burns hotter. The hotter the burn, the more NOx emissions you get. Also the more your cooling system has to work to keep your power plant nice and cool.
fightingfalconfan There is no more potential energy in a gallon of regular gasoline than in one gallon of premium gasoline. A higher octane fuel, which has a lower heptane ratio, rating improves the engine's resistance to knock. Engines with higher compression, such as in BMW engines, will require higher octane fuels because this extra compression of air may combust low octane fuel prematurely.
Curious. Will the car's ecu will control the individual cylinder's ignition timing to optimize the performance based on the fuel's octane? Also, will the computer also sync the cycle of the cylinders for best effectiveness?
Important note: You will only gain power if you have an engine that uses knock sensor(s). Another benefit of a higher octane is that you can increase the compression ratio of the engine without getting knock due to premature ignition of the fuel.
Robin Karlsen My R18Z1 has knock sensors and it runs like crap on higher octanes. Runs EXTREMELY rich getting 25mpg highway, where I get 45mpg average per tank. The knock sensor just allows the engine run on the different octanes without destroying itself, it doesnt mean the computer will optimize the timing for the different octane.
Nick Palaroan It sounds like you have a weak ignition system or fouled plugs. It takes more heat to ignite higher octane, which is the whole point. Your car tunes the timing to be on the threshold of detonation to get the most power and the best fuel economy. When you raise that pre-detonation threshold by making the fuel harder to ignite, the computer indeed advances the timing map.
GioGuitarDude So my brand new car has fouled plugs or weak ignition system? I doubt it. Im not saying some cars wont benefit from higher octanes, Im saying that just because a car has a knock sensor doesnt mean it will benefit from it. It depends on how the computer was programmed in the car.
+GioGuitarDude It also depends on the compression ratio. The R18Z1 is 10.6:1, which isnt all that high for 87 (US) octane today. If your fuel is igniting at the proper point after compression, then increasing the octane will at best have no effect on the performance of the engine. Since the higher octane can withstand higher compression, knock shouldnt be experienced at all in this scenario. Knock is experienced when your octane is too low, not too high.
Also, performing this test on a turbocharged car is not representative of all cars, as its high compression ratio (thanks to the turbo) allows it to take advantage of higher octane fuel to prevent knock. Most economy N/A engines don't have the compression ratio to use higher octane fuel in a more efficient fashion, as they are tuned to efficiently run on 87 and can't much advance timing when using anything higher. This is an assumption based on what I know.
Engineering Explained Forced induction engines already compress the air so although they have lower geometric compression ratio than NA engines they typically have higher effective compression ratio, thus the high octane requirement.
How come many higher elevation states have as low as 85OCT gas? The elevation difference on the engine will allow it to even run lower octane and not produce knock? Is that how it works?
Very cool video!? what software did you use to get your reading? Labview? I want to learn some data acquisition, i loved how you set up that live feed of your data!
Can u please do a video explaining the relevance between compression and horsepower,how much more compression equals how much more horsepower? How much horsepower will I get by simply changing my pistons to a higher compression piston?
Possible video idea. Lightweight crank pulleys. Pros,Cons, long lasting effects. Better for modded engines? what can they do to stock engines? Better for n/a or turbo?
Bro need to touch on how some cars are officially recommended to use lower octane especially cars. Theres no increase in power if you dont have a sensor to take advantage of the early detonation.
+Paul Anderson for EVERY fuel or oil additive: waste of money. Most don't do what they say, some do but to so little effect that you may as well have not even used it, and oil additives ruin the careful, specific balance of additives already found in today's oils. You're best off just using what comes with the gasoline and/or oil
I have done hours of research on this and don't feel like I've got anywhere. I just leased a 2015 Cruze 1.4L turbo. Would my car benefit from higher octane fuel? Especially with the turbo? Some forums say yes others say no. Some say it will improve gas milage considerably and some say higher octane fuel would hurt my gas milage. What is the truth? Thank you for your help! Loved this video by the way.
Brett Walden Try to find out if your car has a knock sensor. If it does, chances are high you would benefit from the better fuel. If it doesnt you wont benefit from it in term of power and could even lose some power under some circumstances. You will however get slightly better miles/gallon. But considering that premium fuel is more expensive you will not get more milage/money. Considering it's age I would guess that your car would benefit from the better fuel.
Premium only on anything with boost. If you are NA you can get away with 87 as long as you aren't knocking or experiencing a noticiable reduction in power or mpg
I thought lower octane fuel would lead to the spark igniting earlier since the air fuel mixture would be more susceptible to pre-detonating. Could you tell me where I got it wrong?
7150285 Don't think you quite got what I was saying in the video. You can ignite higher octane fuel earlier with a spark (not compression) than lower octane fuel without having knock. Pre-ignition is something different (combustion via compression) and not what this is referring to.
Great video! What would be de power increase using the HighOct fuel instead of the lower one? ...basically, how much power gain (average) can be expected ?... (I know it can vary etc... just a average... )
Hi, you have quite a lot of excellent videos, and I think I have a good idea for a new one. Maybe you could explain the procedures you have to follow to get an appropriate dyno testrun and the errors you would get making certains mistakes. My question more specificly is about the gears you are into when on the dyno run, I know it influences torque but not the HP... what is the reference, etc. Can you help ? Thanks !
my father had a ford ranger 2.5 turbocharged 2WD but only make 130km/h , feeling that engine is losing power a lot while going up hill ..... what's the main problem ? engine seems no weird sound no black smoke ( thanks for solving )
Damn, just realised this was old! Question 1 - Does the advantage only apply to engines that have the ability to self adjust timing? Question 2 - Any way to tell if my 2013 Subaru Forester FB25B would really benefit from this? Question 3 - In Australia the price difference between 91 and 95 - 98 Octane fuel is very significant, so even with the better performance of the high octane fuel, is my economy shot thanks to the over zealous pricing of the premium fuels? My circumstances if relevant - The Subie is a daily driver, not looking for race track performance, but i do care about looking after it.
See in my old car I had an issue where the car would jolt in 2nd gear and judder all over the place, that was using 95 RON. I decided to trial the 99 RON as at the time the price as barely any difference and it cleared the juddering. However why would that be if the car is designed for 95 RON?
can you do a video comparing 10% ethanol fuel mix vs. no ethanol fuel mix? In terms of how far each can go and if that increase in mileage is worth the price increase.
I have same thoughts as some others about the octane but the test needs clarification . I can best display this with cars i a familiar with to give what i think is the test error . A 98 saturn SL1 states in the owner guide to run ONLY 87 OCTANE where as an 87 pontiac sunbird gt turbo states HIGH OCTANE FOR BEST PERFOMANCE . No doubt the sunbird would have same results as the video, but would the Saturn? Theoretically it should have oppisite effects of the video because the cars computer system is specifically programmed for the timing effect of the 87 and therefore the 93 &94 octane is a waste . To remark on another comment about civics ... yes and no . Higher rpm engines and tweeked engines would usually require higher octane due to the faster timing involved with an 8500 rpm engine compared to a 5000 rpm engine . NOT ALWAYS but it is the general rule of thumb ( yes there are exceptions on both sides, especially with todays newest engines ) .
Can the cameraman go on a filming course? It was wierd listening to the engineer with his head cut off. The constant zooming in and out was disorientating.
To start off I just wanted to say I'm a fan of your videos. I was wondering what effect does elevation have on octane and what would happen if I ran a 93 tune using 91 octane? Thank you for your time
At higher elevations the air has less density and also less oxygen content. Therefore cylinder pressures will be slightly lower, and you may or may not be able to get away a with more timing via the tune. I personally wouldn’t recommend it however as the oxygen content and density is less of a factor than than you would think compared to the timing curve changes.
My 2013 Honda CR-Z runs exclusively on Frank’s Red Hot sauce just like the manual says
do you know where I can find the shell video?
Dude stop
I like how you provided facts and real test results in your video instead of just talking about it like everyone else. Great video! I have a better understanding of this now.
Very interesting because I didn't know that the ignition timing would be adjusted per-cylinder like that.
SirBudrick In newer engines it can.
SirBudrick me neither
That is why a knock sensor was installed in modern engines😉
@@mohamedgaaloul2753 knock sensor doesn't necessarily mean per cylinder adjustment. Lot's of older EFI cars had just one knock sensor and would not even immediately know which bank on a V engine is knocking until it made adjustments to STFT and observe if it helped or not. With port injection, and sometimes batch fire during startup or even steady state on some older EFI ECU you don't always even know for sure which injector to adjust until several cycles of making adjustments and observing plant response.
this is my take on octane: With high octane fuel, it is refined to slow down the combustion speed and drag it out over a longer period of time. So, it ends up being a cooler, but longer burn than low octane. Because of that, timing can be advanced a bit more. My experience shows that only under heavy acceleration, or load, the engine shows it's true colors. As most of us know, all modern gas auto engines have a computer with knock sensors that "listen" for knocking (early combustion) and adjust the timing dynamically to stop it. So, with that being said, IMO, if you do a "butt dyno" making runs using 87 oct and again using 100 oct racing fuel, ya....you may notice a bit more punch with your daily driver. Worth it? Naa. That's my own opinion on the topic.
but, when there is a noticeable difference btw 87 and 91 pump... it suddenly makes sense
You’re wrong in almost every way, amazingly.
some engines are made to run on 98, like the TSI. it is worth it in those cases.
I switched to the premium gas for the increase in detergents. I have also noticed an increase in performance. Worth the increase in price.
That's why they told me to run premium in my motorcycle despite handling low octane fine
Thanks
your videos are usually spot-on. the truth of the matter is higher octane fuel has less BTU or chemical energy than 87 octane. octane is a function of compression ratio and actually requires more ignition timing because the higher the octane the slower the burn. this subject is way more complicated then even I can get into in a comment section TH-cam video
Buck Ding so don’t comment then. At least EE is educating people
Even you eh? Tool bag
It's also interesting to note that lower octane fuel ignites quicker which can give you better throttle response and improved economy. Some cars feel sluggish on high octane, my Ecotec 2.0T feels deluxe on 91 but it still goes like hell on 87. No knock, I just hear the turbo. I'll give it 91/93/94 for the mountains but around town it seems 87 is just fine.
TSI engines from VW are made to run on 98. 95 can cause knock, 92 is too low.
I notice the difference between Sunoco high octane and the Shell V-Power Nitro+ in my Porsche 718 Cayman S PDK. It's got the extra edge as a result of the 99 RON. With a 3.6 second 0-60 mph time, it can be difficult to perceive the difference, but it is there.
very cool video. also, I didn't even realize modern engines could change the timing of each cylinder independently. that's INCREDIBLE!
Most satisfying video available
All of this is dependent on the timing of the cam shaft and ignition with the position of the piston. A car meant for unleaded 87 octane can run better with 87 octane rather than 93 octane, if the timing was maximized for 87 octane.
Now this is what I've been looking for!! Yes I'm that person asked you on octane and power on FB Jason... Thank you very much as always!! so Higher octane can possible result with more power (of course this doesn't apply to all cars)
Finally a demonstration that show how that actually works out. I always assumed that if your engine doesn't knock on the lower octane fuel then you wouldn't actually see any anti-knock benefit with going with the higher octane.
Yea, that's not true with the newer cars, since they just pull timing to prevent the knock. My supercharged Grand Prix is that way. Run regular unleaded all you want, runs fine. Run premium in it, the computer throws the timing back in and you're up about 30 HP.
@@RotaryTurbofascinating thx
I used Shell V-Power 93 Octane for my road trip to Boston on the weekend of New Years. The vehicle is a 2014 Subaru Forester 2.5 Touring with EyeSight. The engine does have direct injection, although required octane is 87. At cold temperatures, 87 lowers fuel economy when I drove to Albany last year to visit my sister at the time. Shell V-Power 91 or 93 has 5 times more additives than their 87 octane, and if you have a direct injection engine, requiring regular or premium gasoline, use Shell V-Power once every 5,000 miles to remove and prevent carbon build-up on injectors and in some engines, intake valves.
Higher Octane Fuel produce Less Energy per liter thus Lower Octane fuel give you more mileage
+Tim Joseph You're not going to clean your intake valves with fuel on a direct injection engine no matter the grade or how many detergents it contains. Direct injection combined with EGR is WHY you see heavy buildup in the intakes; no fuel in your intake to do the cleaning.
Carburetors and single point fuel injection systems had no real issues with carbon buildup because everything was constantly soaked in fuel and cleaned.
I own a 2001 mustang and I’ve been using 83 for so long so I decided to switch to plus gas, I actually noticed a bit more power in acceleration. Then I tried premium in it, and noticed a tad bit more power and man I’m liking it, cause the V6 isn’t too fast in the first place but it makes it seem a lot more powerful.
I really like the way you explain difficult things budd. good job
It depends on what your car is tuned for as you said, you might not want the timing too fast and the piston still be on it's way up. That would creat higher pressure but would give you much less power.
shell is cheating, this car engine is designed to run higher octain fuel. this does not apply to most cars.
All car are different, from manufacturer to manufacturer, turbo to NA, and country to country. Shell chose a car that can cope with the requirements of the test. So what?
Premium fuel has benefits for hp and as a result, economy. That's a fact. All engineers know this. However, some cars are programmed to give those benefits and some are not. I don't understand why, but this seems to me more common in the American and Canadian cars than elsewhere.
Pavel Kovalkov nope this is 1.4 or 2.0 engine such as Gti so in Europe designed to run with 95ron but could detune for 93ron.
Whereas in US, it is usually speccd for 93ron and can be tuned to 95ron if used
Steven Farrington Premium fuel does NOT have any performance or efficiency advantage in an engine not optimized for it.
+Nick Palaroan Hondas sold in NZ from '96 on used knock sensors to detect octane and automatically adjust giving a hp boost as octane rating rose. This is what we service technicians were taught by Honda NZ and the info came straight from Honda Japan. The PGM-FI was fast enough to adjust for a different octane rating every stroke. This technology is everywhere now but it seems that some manufacturers still cut costs by optimising for low octane only. The sort of person who thinks a Corolla is worth buying wouldn't be able to tell the difference anyway.
Steven Farrington
The problem with using a fuel with a higher octane rating, than specified by the mfg, is that the car cannot detect higher octane at all. The sensors detect knock (ostensibly from too-low an octane) and adjust the timing until the knock goes away. If the engine is rated for 91 octane and there is no knock from that gas, then adding 93 will do nothing. The car can't tell one from the other. In fact, using a higher octane than specified can actually reduce performance and increase pollution.
You should do this video again but with a n/a economy car. There is so many people wasting money putting race gas in their "performance Civics" around where I live and I'm wondering if higher octane gas even makes a difference on those cars. I'm guessing the answer is no considering those cars weren't tuned for anything higher than 87 octane, unlike the turbocharged golf in this video.
Lawrence Timme You have a different method to determine octane rating. Our 87 is the same as your 95.
Lawrence Timme In the UK, petrol is rated using the RON standard, us Americans have our fuel rated using the AKI standard. That's why the octane numbers differ so much.
Lawrence Timme
Who is AKI?
A golf is an economy car!
Cantenkerous Tim It's a turbocharged economy car. Meaning it's a performance economy car, unlike the Civics in my town.
You can't necessarily hear uncontrolled combustion events (aka, 'pre-ignition', or 'knock') from inside your car. It actually has to be pretty severe to be audible. So which fuel to use was a much more critical decision, in the days before EFI and knock sensors. Back then, for the vast majority of applications, the object was simply to protect the engine. Carburetor and ignition tuning were conservative, and more stable 'high-test' fuel provided additional insurance.
There was a laborious process of 'spark plug reading', followed by ignition and carburetor tuning, used in racing to extract maximum performance. But it was only good for the specific current ambient conditions (barometric pressure, temperature, humidity). Not very practical or useful in a daily driven car.
Once self-adjusting engine management and knock sensors came along, an engine could take advantage of premium fuel to produce more power safely. Given what Shell V-Power costs, the question is whether a slight power increase justifies the expense. Bottled injector cleaner is a cheaper way to get better fuel system cleaning. So, are you running around at max throttle and load on the street? Or racing your car professionally? Probably not. It's your money...
Thank you for this video, I was trying to explain this to my friend but I haven't been able to really explain it to him well (I've only just started engineering classes). I'll be showing this to him asap!
It's like gun pouder you want the burn to not stop till the shot leaves the barrel. If it does the bullet has barrel drag and slows down. Same as high or low octane fuels .
Love your videos, I learn a lot. One recommendation I have is increase the lighting in the room where you're filming. You can bounce a light off the ceiling or add a soft box with bulbs.
I’ve always run 93 octane fuel and have never had any major mechanical issues in my vehicles. It sparks faster and runs more efficient especially in high performance cars that’s one thing I’ve never understood when people use 87 octane in a powerful v8 especially for racing just because they want to save 5 bucks at the pump for me it’s totally worth it and the science backs it up.
Well, actually, the higher the octane rating of the fuel, the HARDER that fuel is to ignite & the MORE heat is required to ignite it! They also burn slower than lower octane fuels as well...
I don't trust Germans around dynos...
+Greg Rosenberger lol. i wonder why.
Ron Swanson not to mention Volkswagen haha
Shell is Dutch, not German, so...
Ron...or gas! 🤣🤣🤣
LOL
I did a test on a long drive across Pennsylvania where I used 87 octane on the way out and 89 octane on the way back. Not surprisingly, the 89 octane gave me better mileage. The next step was to compare the increase in mileage to the increased price of the 89 octane fuel. The result? Although I got better mileage with 89 octane fuel, it actually cost me more per mile to run the car. So...I'm actually better off running the 87 octane and getting less MPG. If I were doing a Track Day, 89. Day to day commuting...87.
Dope. I wish this tech had been around back when I argued basic chemistry and physics with my auto shop teacher (turns out I was right). Of course, at the time, we didn't have advanced EFI systems with on-the-fly advance and knock sensors on cars we could actually work on in the shop.
My 2018 Mazda CX-9 takes off when using Shell V power. It can alter ignition timing. Though premium isn’t required, regular 87 gives 227hp, with 93 giving 250.
My 2017 Volkswagon Gti will get a slight bump in power with the high octane but as shown in the video will adjust and run fine on regular gas as well with almost un-noticible performance. The cost of the high octane is not worth the benefit so I don't use it on a regular basis. I fuel up with high octane a few times a year because it has fuel additives that are beneficial to cleaning the injectors that the regular fuel don't have.
This is only one part of the explosion. The higher your compression in the car, the faster it will detonate. Some cars don't produce the heat and pressure required to run (explode/combust/tear bonds) of higher octane (more carbon bonds) fuel.
bon vivant Correct, which is why this was tested with a vehicle which desires premium fuel. Cars requiring regular fuel will not see a benefit.
Yes, but let's use 103 octane on the same car in an Alaskan winter and see what the conclusion is.
The point I'm trying to make is that people have unfortunately concluded that higher octane means more power, and that is far from correct. You need the right octane for the right car and condition. Track temperatures can be significantly higher than ambient, and driving behind another car can increase engine temperature from lack of cooling. True wind speed and cooling systems, engine load, compression, spark (plugs), and radiant heat all play a role in how a car detonates.
I still see guys putting premium fuel in cars that can take 87 while commuting in them in cold winter conditions. Then they wonder why their engine is knocking.
In many cases, they are wasting money and getting less performance.
+bon vivant My car have's 10.5@1 compression and tempetures here in Puerto Rico are about 91 to 97 were I live. I've tried with gasolines from 91 oct. to 93 and still knock! it's a 2012 lancer gts 2.4l
My question is, can it be a lean problem? The car is 100% stock!! and have's 30,000 miles on it. Spark plugs are completly yellowish brown.
Sorry to hear that Luis. Dark plugs are usually from carbon buildup from fuel that isn't burning completely. Take it to the shop and have them tune it. I wish you luck with this.
+bon vivant thanks bon, I'm in the process of learning how to tune and my car's oem ECU can be reflash :)
Sponsored by Shell... I'm sure this won't be biased whatsoever.
As always you are the best. My favorite channel.👍
But to have a difference, the engine must be designed to use higher octane gasoline, right? If the engine already reaches it's best performance with regular gasoline, there won't be any difference in pressure by using a higher octane gasoline.
uh, not necessarily... there are many factors there... compression ratio, ignition timing, fuel mixture, air pressure/density/temperature.... octane is just part of the story... there are other additives in fuels that can also be a factor... not all fuels are created equal, but the standards in the US make them pretty darn close. etc... etc... you almost have to take it by a case by case basis depending on what engine you have.
Shell determined that Shell V power performs better than regular old Shell in a Shell V power optimized car on a dyno.
Ignoring the conflict of interest, 3% performance boost doesn't seem worth an extra $5 a tank (or more) IMHO.
Great video, I was just finding a bit of humor btw
Its all sponsored by shell, so of course they will want you to buy the most expensive fuel. Run the fuel your manual recommends as there is no real gain in running the higher octane.
+geejaybee413 of course, as mentioned the vehicle needs to require premium to benefit from it.
I am not a shill but honestly shell fuel and shell/pennzoil oil is really the best of the best ... Pretty much every high performance manufacturer recommends shell fuel and ferrari only uses shell/pennzoil oil..
I ONLY run Shell in my high compression snow blower as per 2 mechanics advice.
The performance with the premium gas is miles away from the other levels.
My car gets it's best MPG on shell basic and I run Marvel Mystery oil.....cheap walmart 4 OZS in gas tank 8 OZS in oil for cleaning and lubrication.l and get 40 % less friction and 40 % higher MPG at 60 mph for the last 2 years.
But I can't buy the octane recommended for my car,all octanes sold are too high and too expensive.
Charley Bomps
I ONLY run Shell in my high compression snow blower as per 2 mechanics advice.
The performance with the premium gas is miles away from the other levels.
My car gets it's best MPG on shell basic and I run Marvel Mystery oil.....cheap walmart 4 OZS in gas tank 8 OZS in oil for cleaning and lubrication.l and get 40 % less friction and 40 % higher MPG at 60 mph for the last 2 years.
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its more than just ignition timing. It's also about the turbo boost. regular fuel will decrease the boost pressure which reduces effective compression ratio, which reduces knock, and obviously lower hp.
Well put young man!
Personally I'm more interested in using the ESSO synergy +99 as it has no ethanol, as the ethanol is reaking
havoc amongst older petrol engined
vehicles, destroying 'o' rings cork seals etc. I'm not knocking the other brands though. No pun intended.
Without knowing all the details; higher octane fuel makes my bikes accelerate faster and gives me a higher top speed. I have tested this in Germany where I can actually reach top speed legally.
Mouldy CPU actually you do what you eat is fuel
Great! Thank you! I have two other engineering questions for you that im sure you will be able to answer for me, but they require a video to ask it, once I figure out how to do that I will send it your way :)
great video
I have a 4 litre turbocharged 6cyl engine running liquid LPG injection. It runs way better on LPG than even premium because LPG is up to 110 octane so the tune winds up the advance. I use premium gas in the petrol tank because it's only used for a brief period after start and Premium has more detergents to last longer and be cleaner. I can only thrash my car on LPG though as it pings on anything else.
Hi, im writing you from France. First of all, thank you very much for the quality of your videos and explanations. I was wondering if you plan to do a video about e85, flex fuel and stock vehicles using this type of gas without any kit or whatsoever having their car working fine thanks to the ECU and injection stock tolerance. It is extremely difficult to know whether it is dangerous or not for the engine, no one seem to have a proper answer about it. Some seem to use e85 on a daily basis for years without encountering any problems, though others explain that it might harm the engine... It would be nice to have your view on the question ! Anyways keep up with the good content :)
Stock timing maps of regular cars usually won't allow any adventage of using high octane fuel. To have any power gain, you would need to tune timing maps first.
andrew aswert Agreed as they have to accommodate all fuel maps, but some systems (modern ones) are capable of altering timing based on fuel used (as demonstrated).
Very informative Video. Well done. It would be even more interesting if You would have tested the real benefits from higher octane fuel when driving a normal car as this Golf 6 on the road
We can already tell you, it probably runs better and gets slightly better mileage. This is a general constant, however you may not notice gains in your particular car, especially if the compression ratio isn’t high enough to take advantage of the higher octane fuel.
my 2002 sentra spec v says to run 91, I noticed running lower grade the knock. 91 it sounded better and got better mpg.
Also most had modified the knock sensor to let it become LESS sensitive.
I'm not an engineer, but I do understand the mechanics of how this works. All the posters comments are dead on! I do have a problem with two cylinders running on one gas and the other on a different gas. They should have, as mentioned earlier, ran a test on all 4 cylinders on one type of gas, then on the other higher octane rated gas, and gone from there. As far as timing goes, they should have not done a pressure test on 2 vs 2, as the engine pistons are connected and even one cylinder affects the other three. I see the point here, but believe it is psuedo-science to promote a fuel that could have been tested much more EFFICIENTLY ON A DYNO.... lol. HIGHER PRESSURES COULD BE FROM KNOCK, SO WHO KNOWS... TIMING IS IRRELEVANT AS THE PISTONS ARE CONNECTED AND "play" off of each other......
+phillys976 The crank bearings were like oh hell no!
Everyone tells me I waste money using the higher octane, they say it makes no difference. I have a big mtn just outside of town, if I set cruse control at 40 the truck slows down and shifts which speeds it up then it shifts again. It does this shifting back and forth no matter what I set cruse at. When I use higher octane it gives just one steady pull up the whole mtn. I also get more miles per gallon, not a lot but some. At the end of the day, even with greater MPH I'm still paying more for the higher octane. I'll pay it for the better performance and better mileage. I have tore down a couple motor's after using the high octane for a number of years and the inside of motor is clean, hardly any carbon build up or varnishing. Add up the extra mileage, better performance and a much cleaner motor and it's worth the extra money
That guy on shell had some really good hair!
I going to explain in this way, Octane is basically the autoignition temperature, and because air it heats when you pump energy to compress, algo elevates the autoignition point.
If you will go to get an car in which you wan't to put let's say, a 3 bar turbocharger (45 psi) you wan't a fuel good enough to take the pressure without knocking. But if you don't your engine possibly will not burn ALL OF THE FUEL, and you gonna get less power, this is a problem that i get when i decided to conver my old engine to natural gas, with a 120 octane number.
Isn't really octane what gives you more power, is the advancement of the plug and the higher pressures you can work on it what gives a little bit more power, if you got an old mustang v8 N/A with a 8.5 compression ratio you don't really need high octane fuel, because you will possibly lost power.
Vpower is the only fuel I can feel the power difference on my car of all the different fuel I have ever used
Vpower sucks
jack deng You have an awful good imagination.
H Mack I don't have any preference or recommendation,I've just had bad experience with V power.I filled my gas tank with Vpower once and I had a HUGE loss in power,I had to use full throttle going up even the smallest hills and could barely accelerate enough to keep up with traffic ,whereas I can normally pass all traffic as my car is much more powerful than most cars where I live.
agreed, they should test those fuels on a car that doesnt need it like a basic bare bones economy car designed for 87 "regular" to show whether or not youre wasting money on "premium".
It would be really cool if you did a bit on octane boosters. i.e. do they boost octane to the extent that they claim they do. I live in SF California and it's a decent pilgrimage to get 93 octane fuel. i have to drive like 30 min to a station that has 100 octane racing fuel and mix it with 91. I'm not looking to see if they give performance gains or anything like that, just octane ratings.
Another fantastic video, thank you.
Really good explaining!
good accurate test
Shell gas is objectively speaking the best. Oh, Chevron, Sunoco, Mobil and Gulf would like to say different, but first they have to make videos, or no one will tout their claims because no claims exist. Shell is also superior in beating the competition to the punch.
I think you might be confusing a few people that won't go back and watch the octane video because they feel they lernt enough. To fill in the gap.. Octane has a direct relationship with compression ratio and also to how fast it burns. You WILL get less power and reduced MPG if you put high octane fuel into your car that recommends 87 octane fuel, but if your system is designed to run 91 octane and you put 87 then it will choke the system reducing the air intake to prevent knock and of course reducing power and mileage. But if you car runs better with higher octane even though it recommends 87... you need repairs, usually a good tuneup and fixing intake leaks.
Higher octane ALLOWS more advanced timing which makes more power, but the car has to be capable of adjusting for it. Older cars rated for 87 octane will not advance their timing and will not make more power if you fill up with 93. Newer turbo cars or custom tuned cars most definitely will advance their timing and make more power on 93 octane. It depends on the car. Mazda Skyactiv is a good example. It will adjust timing and power output based on what you fill up with. 227HP on 87 Octane, and 250HP on 93 Octane.
Why does everyone assume this is telling you to run premium in your 89 Tercel?
This is purely to show the uninformed what happens when you run lower than the manufacturer recommended rating.
If you want to run higher than the recommended, do it for the detergent packages. Because the car won't be able to take advantage of the extra octane rating.
So from what I understand from this series of videos, there is no harm in putting a higher octane fuel in your car than what its rated for. But if you put a lower octane fuel in then it has a chance to prematurely ignite and cause knock. Is that right? Just wondering because everyone I talk to says that knock can be cause by too high of an octane rating as well.
You are correct. Octane is a number designating a fuel's resistance to knock, so it's incorrect to say higher octane could cause knock.
Forgetting something vary important here...sure it prevents knock, but it also burns hotter. The hotter the burn, the more NOx emissions you get. Also the more your cooling system has to work to keep your power plant nice and cool.
fightingfalconfan There is no more potential energy in a gallon of regular gasoline than in one gallon of premium gasoline. A higher octane fuel, which has a lower heptane ratio, rating improves the engine's resistance to knock.
Engines with higher compression, such as in BMW engines, will require higher octane fuels because this extra compression of air may combust low octane fuel prematurely.
Curious. Will the car's ecu will control the individual cylinder's ignition timing to optimize the performance based on the fuel's octane? Also, will the computer also sync the cycle of the cylinders for best effectiveness?
Engineering Explained needs to check out some videos from Video De-interlacing Explained.
My car is already running the maximum ignition advance setting.
Now I just need to increase the compression ratio until knock occurs.
Important note: You will only gain power if you have an engine that uses knock sensor(s).
Another benefit of a higher octane is that you can increase the compression ratio of the engine without getting knock due to premature ignition of the fuel.
You can't get a higher compression ratio without doing major head work
Robin Karlsen My R18Z1 has knock sensors and it runs like crap on higher octanes. Runs EXTREMELY rich getting 25mpg highway, where I get 45mpg average per tank.
The knock sensor just allows the engine run on the different octanes without destroying itself, it doesnt mean the computer will optimize the timing for the different octane.
Nick Palaroan It sounds like you have a weak ignition system or fouled plugs. It takes more heat to ignite higher octane, which is the whole point. Your car tunes the timing to be on the threshold of detonation to get the most power and the best fuel economy. When you raise that pre-detonation threshold by making the fuel harder to ignite, the computer indeed advances the timing map.
GioGuitarDude So my brand new car has fouled plugs or weak ignition system?
I doubt it.
Im not saying some cars wont benefit from higher octanes, Im saying that just because a car has a knock sensor doesnt mean it will benefit from it. It depends on how the computer was programmed in the car.
+GioGuitarDude It also depends on the compression ratio. The R18Z1 is 10.6:1, which isnt all that high for 87 (US) octane today.
If your fuel is igniting at the proper point after compression, then increasing the octane will at best have no effect on the performance of the engine. Since the higher octane can withstand higher compression, knock shouldnt be experienced at all in this scenario. Knock is experienced when your octane is too low, not too high.
Well explained. Thanks!
Also, performing this test on a turbocharged car is not representative of all cars, as its high compression ratio (thanks to the turbo) allows it to take advantage of higher octane fuel to prevent knock. Most economy N/A engines don't have the compression ratio to use higher octane fuel in a more efficient fashion, as they are tuned to efficiently run on 87 and can't much advance timing when using anything higher. This is an assumption based on what I know.
Turbo engines typically have lower compression ratios, due to the high pressure from the turbo. I believe this car was NA.
Engineering Explained It was a Golf TSI. I don't think VW make a non-turbo'd engine and put a "T" badge on it... ("think" being the operative word)
Engineering Explained Forced induction engines already compress the air so although they have lower geometric compression ratio than NA engines they typically have higher effective compression ratio, thus the high octane requirement.
How come many higher elevation states have as low as 85OCT gas? The elevation difference on the engine will allow it to even run lower octane and not produce knock? Is that how it works?
Very cool video!? what software did you use to get your reading? Labview? I want to learn some data acquisition, i loved how you set up that live feed of your data!
You should make a video on lightweight Pulley Expalined
Can u please do a video explaining the relevance between compression and horsepower,how much more compression equals how much more horsepower? How much horsepower will I get by simply changing my pistons to a higher compression piston?
Was this test conducted at idle? Would be interesting to see results under varying loads/rpm and boost from the turbo charged engine
Possible video idea. Lightweight crank pulleys. Pros,Cons, long lasting effects. Better for modded engines? what can they do to stock engines? Better for n/a or turbo?
That's why I'm asking the question. I'd don't know what will happen and I'm trying to find out.
Okay cool thanks, makes sense to me!
Bro need to touch on how some cars are officially recommended to use lower octane especially cars.
Theres no increase in power if you dont have a sensor to take advantage of the early detonation.
Hey Jason. Good video you're always good at explaining very technical stuff. What is the horsepower difference between the two fuels?
do you know where I can find the shell video?
I'd love to hear your thoughts on micro lubricants like ZMAX. - Good - Bad - Wast of money???
+Paul Anderson for EVERY fuel or oil additive: waste of money. Most don't do what they say, some do but to so little effect that you may as well have not even used it, and oil additives ruin the careful, specific balance of additives already found in today's oils. You're best off just using what comes with the gasoline and/or oil
I have done hours of research on this and don't feel like I've got anywhere. I just leased a 2015 Cruze 1.4L turbo. Would my car benefit from higher octane fuel? Especially with the turbo? Some forums say yes others say no. Some say it will improve gas milage considerably and some say higher octane fuel would hurt my gas milage. What is the truth? Thank you for your help! Loved this video by the way.
Brett Walden Try to find out if your car has a knock sensor.
If it does, chances are high you would benefit from the better fuel.
If it doesnt you wont benefit from it in term of power and could even lose some power under some circumstances.
You will however get slightly better miles/gallon. But considering that premium fuel is more expensive you will not get more milage/money.
Considering it's age I would guess that your car would benefit from the better fuel.
No Name get a different car
@@Hellsslave666 his car has knock sensor .
Premium only on anything with boost. If you are NA you can get away with 87 as long as you aren't knocking or experiencing a noticiable reduction in power or mpg
I thought lower octane fuel would lead to the spark igniting earlier since the air fuel mixture would be more susceptible to pre-detonating. Could you tell me where I got it wrong?
K Sadek Pre-detonation is unlikely, but knock can happen as the pressure and temps are much higher. Octane number is a fuels resistance to knock.
I thought it's the opposite, I think lower octane will ignite earlier before the piston reach TDC therefore it'll causes engine knock
7150285 Don't think you quite got what I was saying in the video. You can ignite higher octane fuel earlier with a spark (not compression) than lower octane fuel without having knock. Pre-ignition is something different (combustion via compression) and not what this is referring to.
10/23/2018
What changes the timing? The engine’s computer?
Correct. The ECU.
have you done video on e85 ethanol? i would love to see more on e 85 ethanol.
Can you make a video on things to look for when buying a used car?
Premium fuel is for cars that are designed to use it, some cars get worse gas per mile if they run premium fuel because they are designed that way.
+SacreDro I would always recommend for people to use what their owners manual recommends.
Exactly, my fuel cap says RON 91/95 and premium is 98. Used a couple of premium gas but no difference in miles per gallon or in my case km/l.
Waiting for that video on Koineggegs new turbo charger
This ignition timings are made automatically ? I've been using V-Power the last 3 months, and the autonomy is higher by almost 2km per L
zat guy is so german it hurtz my ears....
Yes i'm allowed to laugh about the accent because I'm german myself.
Im so jealous, if i made fun of. him then i would sound raciest*
That is Herr Flick, or is it Herr Lipp? His English and syntax is very good
So, for me to get the most from my ep3 civic, I should run 99 RON fuel? :-)
So finally what's the conclusion? Will shell VPower Gasoline work for 10-10.5:1 compression ratio gasoline vehicles ?
did a tsi engine by volkswagen is twincharged turbo and supercharged
Great video! What would be de power increase using the HighOct fuel instead of the lower one? ...basically, how much power gain (average) can be expected ?... (I know it can vary etc... just a average... )
can you please add a video regarding E85, flex fuel and conversion kits of old carburetors and/or EFIs. Thank you
Is this test on a car that recommends premium?
you dont get knock on modern cars because the ecu corrects the "knock" problem before it even happens
Hi, you have quite a lot of excellent videos, and I think I have a good idea for a new one. Maybe you could explain the procedures you have to follow to get an appropriate dyno testrun and the errors you would get making certains mistakes. My question more specificly is about the gears you are into when on the dyno run, I know it influences torque but not the HP... what is the reference, etc. Can you help ? Thanks !
my father had a ford ranger 2.5 turbocharged 2WD but only make 130km/h , feeling that engine is losing power a lot while going up hill ..... what's the main problem ? engine seems no weird sound no black smoke ( thanks for solving )
Check about ford ecoboost carbon build up, fords are having that issue with their turbos
Damn, just realised this was old!
Question 1 - Does the advantage only apply to engines that have the ability to self adjust timing?
Question 2 - Any way to tell if my 2013 Subaru Forester FB25B would really benefit from this?
Question 3 - In Australia the price difference between 91 and 95 - 98 Octane fuel is very significant, so even with the better performance of the high octane fuel, is my economy shot thanks to the over zealous pricing of the premium fuels?
My circumstances if relevant -
The Subie is a daily driver, not looking for race track performance, but i do care about looking after it.
damn, you have some nasty fuel in America, i'm running 99 Octane in my Ford Puma here in the UK :D
arthur scroggins Different system: th-cam.com/video/zf-OYXlhJis/w-d-xo.html
See in my old car I had an issue where the car would jolt in 2nd gear and judder all over the place, that was using 95 RON. I decided to trial the 99 RON as at the time the price as barely any difference and it cleared the juddering. However why would that be if the car is designed for 95 RON?
can you do a video comparing 10% ethanol fuel mix vs. no ethanol fuel mix? In terms of how far each can go and if that increase in mileage is worth the price increase.
I have same thoughts as some others about the octane but the test needs clarification . I can best display this with cars i a familiar with to give what i think is the test error . A 98 saturn SL1 states in the owner guide to run ONLY 87 OCTANE where as an 87 pontiac sunbird gt turbo states HIGH OCTANE FOR BEST PERFOMANCE . No doubt the sunbird would have same results as the video, but would the Saturn? Theoretically it should have oppisite effects of the video because the cars computer system is specifically programmed for the timing effect of the 87 and therefore the 93 &94 octane is a waste .
To remark on another comment about civics ... yes and no . Higher rpm engines and tweeked engines would usually require higher octane due to the faster timing involved with an 8500 rpm engine compared to a 5000 rpm engine . NOT ALWAYS but it is the general rule of thumb ( yes there are exceptions on both sides, especially with todays newest engines ) .
Can the cameraman go on a filming course? It was wierd listening to the engineer with his head cut off. The constant zooming in and out was disorientating.
To start off I just wanted to say I'm a fan of your videos. I was wondering what effect does elevation have on octane and what would happen if I ran a 93 tune using 91 octane? Thank you for your time
At higher elevations the air has less density and also less oxygen content. Therefore cylinder pressures will be slightly lower, and you may or may not be able to get away a with more timing via the tune. I personally wouldn’t recommend it however as the oxygen content and density is less of a factor than than you would think compared to the timing curve changes.