Race gas for performance

[whiteM5]

I've been runnning 100 octane in exotic cars for a while, but was wondering if anybody is using it in their f10 m5.

if so how high are you going? my local dealer has sunoco 109, wondering if i can get away with that in the m5 as well? anybody run 100? or higher?

how'd it go?

[carholic]

I have tried mixing 100 to 91 and get around 94. In my other cars ( Porsches and Ferraris) I noticed the difference. Surprisingly, on this car, I don't notice the difference when I switched it back to just 91. Even compared to when the car was running 98 in Europe, the 91 here feels the same. I am very surprised.

[stealth.pilot]

Originally Posted by carholic

I have tried mixing 100 to 91 and get around 94. In my other cars ( Porsches and Ferraris) I noticed the difference. Surprisingly, on this car, I don't notice the difference when I switched it back to just 91. Even compared to when the car was running 98 in Europe, the 91 here feels the same. I am very surprised.

98 in Europe and 91 here are the same thing. We have different octane scales just like a Us gallon and an Imperial gallon are different.

[carholic]

I think 98 in Europe equals 93 here. However, here in California, we only get 91 unless we mix it with 100 to get 93. What I am saying is that with tanks of 91 vs tanks of 93, I could not tell a difference on this car. I wonder if this car was already tuned from the factory to use 91.