39 thoughts on “Car Tech 101: Octane demystified

  • March 25, 2019 at 3:45 am
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    I have an Accord V6 with aftermarket exhausts and cold air intake..should I use Premium?

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  • March 25, 2019 at 3:45 am
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    , the octane rating for gasoline has nothing to do with the amount of power locked inside of it – it actually relates to just how much a fuel can be compressed before igniting. The higher the number, the less likely it is to ignite under pressure.

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  • March 25, 2019 at 3:45 am
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    I agree that Europe (and pretty much the entire world) only uses the RON number, but Europe's regular gas is 95 RON, which is 91 AKI, which is what is considered premium in a lot of places in the U.S. and even the pump in the video doesn't offer anything higher than Europe's regular. I know that almost every basic car in Europe has at least one turbocharger to increase efficiency, but because of the higher octane, car manufacturers can increase compression and create more power (like a sports car).
    Only a few naturally aspirated "eco" or basic cars, or some cars that just don't care (usually naturally aspirated American V6'es or V8's) can run on AKI 87 (RON 91), but good luck finding it. It's not sold anywhere except for a very few gas stations in Germany and Austria, and the price difference between 91 and 95 is almost non-existant, so why even bother?

    Even a basic 2005 Golf can't take anything less than what would equal to 91 in the U.S., because of it's compression ratio. That'd never work in the U.S. Who would want that?
    Our premium (we only have two kinds of fuel) is RON 98, which equals to AKI 93 or 94 (depening on the station where you get it from), which literally only sports cars take, or older cars because 98 doesn't contain ethanol, unlike 95, and the extra octane is good for very old cars that used to run leaded to prevent knocking.
    I believe Germany even has 100 octane fuel for race cars. And we have autogas which is like 110 octane and about $2,5/gal.

    A lot of BMW's for example can run on 98, but they can adjust their timing to run fine on 95 as well (just with slightly reduced performance). That's fine. A basic Honda Civic that takes 95 will not perform any better on 98. I feel like a lot of European cars in the U.S. will perform better on premium (because it's our regular), like a RR for example, but they're equipped with software to be able to run on the much lower octane ratings in the U.S., Canada and Russia for example as well. You won't even notice the reduced performance when driving from A to B.

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  • March 25, 2019 at 3:45 am
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    I'm glad I traded in my old car with a catalytic failure rather than fixing it because my engine was actually at fault.

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  • March 25, 2019 at 3:45 am
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    Hey so i live in Australia, and our regular unleaded is 91 octane. And premium is 98 octane and normally contains fuel additives and things to clean your engine. There is also 95 octane. Why does America use 87 as a base.

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  • March 25, 2019 at 3:45 am
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    People just don't believe using 93 octane (USA) makes a difference in an 87 octane car.  And we're constantly told that it doesn't.  I have always bought 93 octane and must be a rare person who can feel a difference.  The way you can tell is to buy 93 octane for a couple of months and then switch back to 87.  You'll be wondering what is wrong with your car and about the time you're ready to make an appointment for service you'll remember that you filled up with garbage 87 octane.

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  • March 25, 2019 at 3:45 am
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    I have ran the higher gas because I typically get alittle better mileage.

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  • March 25, 2019 at 3:45 am
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    all gas comes through the same pipe lines that's a fact. Do you think you'll get anything different than low octane from the same pipe?

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  • March 25, 2019 at 3:45 am
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    Pointless information. Can I use 87 in my 2012 Mercedes 250? Porsche boxster, and gwagon?

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  • March 25, 2019 at 3:45 am
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    I'm happy to see a video talk about the real reason for higher octane gas. It's to reduce the chance of premature ignition, which produces what we call knocking. The risk of premature ignition is higher in a higher compression engine. I have used premium gas for years for that reason and that reason alone. For me it's never been about economy/energy/power. It's always been about protecting the engine from knocking. Another thing that I never hear people talk about is how if gas is left standing for long periods of time the octane degrades. That's why they always say to never run your lawn mower in the spring using last year's gas. Drane it out and use fresh gas. When it comes to my car, I want extra assurance that if I don't do a lot of mileage, the octane of the gas standing in the tank does not degrade below minimum specification for my car. Besides, how can I be sure that the gas I buy at the pump has not already started to degrade. My best protection against that is to buy the highest octane gas available. I appreciate the extra additives that some "Top Tier" brands sometime put in their premium gas, but the main reason I do it, indeed the only reason I do it, is to better prevent premature ignition in the engine. I don't do it for extra mileage. I don't do it for more power. I really wish people would stop talking about that. People who talk economy/energy/power only demonstrate that they have no clue what they are talking about. Just look it up on Wikipedia. They make it very clear. As said in this video, the reason for higher octane is to protect against premature ignition which has a higher chance of happening in a higher compression engine. It's all about protecting your motor from premature ignition.

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  • March 25, 2019 at 3:45 am
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    I wish I hadn’t bought a BMW. She demands premium fuel, and anytime I try to cheat, and put regular in, she complains to no end, and gets horrible mpg.

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  • March 25, 2019 at 3:45 am
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    No benefit to running premium gas on a car that the manufacturer says is fine on regular.

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  • March 25, 2019 at 3:45 am
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    Finally ! Somebody honest ! Holy crap yes today's Camry has 10.5:1 compression that used to be GTO territory ! 87 is garbage.

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  • March 25, 2019 at 3:45 am
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    I have a 350 z and I tried 89 did not knock but power is a tad different so I'm not driving it until gas is below 3.00 a gallon

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  • March 25, 2019 at 3:45 am
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    Basically you go by what the car manual says to put into your car. If it recommends Premium then you should put premium. If it says regular unleaded gas then regular is what is needed nothing else. If you have a high performance sports car and it requires Premium fuel only then that's what you're suppose to put in it.

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  • March 25, 2019 at 3:45 am
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    ITT: People that didn't pay attention to the video…

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  • March 25, 2019 at 3:45 am
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    My old beat up Dodge Ram knocks under throttle on regular but not premium……

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  • March 25, 2019 at 3:45 am
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    standard vehicles are designed and set to run on regular. I have 2 high performance cars, a 84 camero z28 and a 87 gt mustang both are designed to run on premium 91 or better octane, put reg. in these cars they will knock and sputter doen the road. newer cars have been designed to run on reg. unless super charged. putting prem. in a car or truck designed and set up for reg. gas, using prem. will affect the performance.

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  • March 25, 2019 at 3:45 am
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    here in Florida on the East Coast I'm starting to see gas stations putting n 15 additive in the fuel what does that mean for our engines I know they put 10% ethanol now they're putting 15% ethanol what does that do to the engine

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  • March 25, 2019 at 3:45 am
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    goddamn.. this is cool. i go through a tank every 3 days or so and i have to use 94. So dont even.

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  • March 25, 2019 at 3:45 am
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    if u go low octane u lose HP and hurt your engine . highr octane will never go wrong .. but if u drive a shity 170 HP Toyota etc .. its a waste of money .. however if you're driving a sport car or a muscle car the higher the better and u can also use race fuel with 110+ octane but that usually requires a tune … i use a high octane fuel and use fuel boost cuz in my lame ass country we only have 95 and 91 and i have gaind 10 hp just from switching to higher octane

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  • March 25, 2019 at 3:45 am
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    been filling my 98 lexus lx470 since i bought it new. 250.550 miles on it and never had a problem

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  • March 25, 2019 at 3:45 am
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    Only if your compression is around 1:13, anything lower than that (95% of cars on the road) won't see any benefit of anything over 87.

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