Originally Posted by shu
95 for me..
I've pumped 4-5 consecutive tanks for 98.. didn't feel any power difference or notice any extra mileage. Went back to 95 after that. I don't see how a difference of 3 octane will do anything bad to the engine?
Could affect your timing - may not feel it though, need to do runs and log it.
Though it is probably ok for a stock car, would still go for 98 on a turbo car...