I run a 3:1 premium 91 octane gas / race fuel mix in my 512 (11.3:1 compression stealth heads) Challenger. My car runs better with it but my 1/4 mile times went from 11 seconds to 11 minutes because I had to stop every 50 feet to get out and smell my exhaust....... God I love that smell.

I was only kidding about the 1/4 mile times I have no idea what it runs in a 1/4