That's a loaded question... Most street engines running less then 10 to 1 compression ratio run just fine on pump gas. When you head on over to your race gas dealer he will have many choices for you! For starters they will ask what you have, nitrous, blower, turbos, high compression pistons etc. This will eliminate many choices if you don't fall into those categories. Next will come how do you drive your car? Do you want to race it, constant high rpm use, street performance, leaded , unleaded, oh my head is spinning. 100 unleaded is a good starting point for most street cars. VP- TRICK - SUNOCO all good stuff!