How Much Difference Do High Octane Fuels Make To Power Outputs?
In this segment the Fifth Gear lot have plucked from their archives, Vicki Butler Henderson investigates "posh petrols" to see how much of a difference they can make to power outputs
To find out more about the differences between high and low octane fuels, check out our guide from Engineering Explained.
Growing up on a diet of World Rally Championship highlights and lengthy Gran Turismo 2 sessions, a life in cars was as good as inevitable for Matt.
Comments
What she failed to mention though is the premium fuels are generally better for the health of the engine, but either way they are not worth the price
Well if the difference is like 10 cents, i think it’s worth getting premium.
What if I told you premium and regular is exactly same “quality” and they won’t damage your engine no matter what you tank. You have been brainwashed by ads
So from what I understood with full tank of cheap fuel you would travel less kilometers than with a full tank of pricier one.
The second thing is that is can prevent knock.
The third thing is the full tank difference in price is equal to a sandwitch and a half…
Not worth the price or you just buy cheaper fuel and you want to believe that it isn’t worth it.
Your car is an extension of your body. If you like eating free range organic products, then you should be filling up your car with premium fuel.
Or you don’t buy free range organic products to safe money to fuel up your racecar…
What if you up the timing and only run on high octane fuel?
Most performance cars have variable timing so they can have an advantage on premium fuels. A Golf GTI isn’t enough performance oriented for this kind of stuff, with a sports or supercar the advantages can be a lot higher.
I can confirm tuning for my car with VP 110 race fuel is a big improvement with no intercooler as the intake temps are so high. At a cost of leaded fuel and 10.00 a gallon…
Ok, so they might be pricey. Bu i have a 1.25 2001 ford fiesta (I know, nothing to shout about). but when I run it on standard fuel at lower revs, I can hear it pre-igniting, esp when driving with a tall wall next to me. but when I used super unleaded. it doesn’t pre-ignite. and you can feel the difference in responsiveness lower in the rev range. but I only use it when I feel like giving my car a little treat :)
Have you increased compression?
And you can get better mpg.
It happened to me not long ago, i got it 20€ of 95 (but a cheap one) and i only did 100-120km, and then i got 20€ of the premium one (95 octane) and i did 200-240km … did the twice the kms on low cruse.
And when i am in the mood i put 98 octane and i make with 10€, same km with 20€ on 95.
And for the price that’s 10-20cents difference, i think i really should use only 98 premium.
Maybe (just maybe) your piston have carbon on them. That could explain the pre-igniting. With the time, carbon keep the heat and can ignite the mix.
the 1.25 Engine needs super fuel. look up in the manual it says it requies ROZ 95
I feel the same thing with my 1.6 2013 rio
COBB tuning will probably disagree as with other tuners of Turbocharged cars…
Sure a stock car is designed to perform similarly with different octane levels but once you tune, 93AKI/98RON has a ton of benefits over 91AKI/95RON.
And then there’s AKI and RON… No, ‘Muricans don’t always get poor gas… Unless they are in California.
Don’t forget North Dakota haha, we have horrible fuel here….
I’m sure they also tried this a long time ago with a Clio, a Subaru, and a Golf. The Subaru got the most benefit from the premium fuel because it’s a higher compression, performance based engine. It’s all to do with compression and how much stress the engine will be put under, it’s the same reason why some tuners put flex fuel systems in and run on Ethanol. However, some fuels will have cleaning agents inside, giving a benefit regardless. I dunno, as long as my Polo and my van can run on it, it’s good to me. Not like they’re going to run any track days soon.
All cars in the UK have to be able to run on 95 RON fuel. However if you had a more hardcore car than the GTi I’m sure there would be a greater difference. A subaru impretza was given some posh fuel and it was up more than 15 BHP
https://www.youtube.com/watch?v=gQghB4asSnI
You can see why this show is so unpopular… Firstly, an engine designed for 98 (golf is 95) will make a bigger difference.. Furthermore, running crappy fuel on a car designed for 98 will increase the wear n tear n lower the reliability of the engine
WOW TOP GEAR is so much more reliable!
Golf has knock sensors and an ECU very technology advanced. So it might adjust a bit the ignition to achieve those power figures. I know people who run 95 in cars which are designed to run with 98, and no problems at all. It all depends on engine and ecu.
Even an old astra with the X18XE engine has knock sensors… But some other engines didn’t have and you had to switch some transistors or relays or whatever they are called if you used 98 octane.
you sure? my polo gti reccmends 98 RON
Only makes a real difference under high compression ratio/high boost circumstances. The higher the octane rating, the less likely to pre-ignite.
I would like someone to test range per tank rather than horsepower, my old car was a 2007 ford falcon 4L straight six, when ran on 91ron would be lucky to get 650kms to a tank, when ran on 98 regularly got 850+ out of a tank, that’s more money in your pocket if the price isn’t too over the top, on average was an extra 12 cents for 98 where I filled up