I had my car dyno'd and the guy had me take out the mix of 91 and race gas and retested with just 91. It made MORE power with just 91. His point was that our cars are lower compression, octane slows down the burn to help contain detonation in high compression engines and actually takes power away. He proved it with before and after runs. I know some guys believe it increases power but ???
I do now run some race gas, expecially on hot days, to help prevent detonation after killing an engine with 87 gas.
If it doesn't add horsepower, let folks do what they want.
Big Dog