this is lots of good info here. right now I have no issue filling up with 93 octane. the price of that sure beats race fuel. I really don't want to go over 11 to 1 right now because I may boost later. at that point I will change the slugs(pistons) and get right back to 9 to 1 and use some boost. that's way down the road. for now I want miles on this car to pay for the investment.