Tel1sps

Is there any benefit to using a 103 oct race fuel in a stock S? I currently use 93 oct and was wondering if I could benefit from race fuel without an ecu upgrade? Would there be any benefit?

Ludedude

None.

Fongu

No advantage.

Octane is an anti-knock index. If your engine doesn't ping/knock under full load then you don't need it. If you had an engine with a higher compression ratio (or "equivalent" FI boost) to produce more power, it would require higher octane fuel.

Modern cars have knock sensors. They detect pinging and then dial back the power to protect the engine. So if anything high octane fuel prevents loss of power.

papa5murf

with the price of gas now... i dunno why you want anything over 93 as it is..

Orthonormal

With the price of gas being what it is, the incremental cost of "premium" may not seem like as big a deal.

Some people may not worry about the price of gas at all. Race gas will be a lot more expensive than pump gas, no matter how much pump gas costs -- the people who think about buying race gas are probably not concerned about the price.

Economics aside, some cars will advance the timing up to a certain point if they can do so without detecting knock. I think most cars that do this reach their maximum timing advance with premium pump gas, and race gas will not provide a benefit. However, I have been told by a source of unknown reliability that certain older Audis can benefit from higher octane than 93. Porsche GT2s apparently do, too. Hmm...I think both are turbo cars.

bridow

yah i wouldnt use 103 unless i had no cats and was running boost or higher compression

silversprint

You can always buy some toluene add it to your gas to raise the Octane and see if it make a difference. Toluene is safe for cats..