A car tuned to run e85 - e100 can show massive gains. Ethanol doesn't detonate or pre ignite, static compression can be raised to over 13:1, it has a linear fuel curve compared to tuning for gasoline, timing can be advanced crazy degrees w/ no pinging issues. Basically if you were to setup and tune a turbo car to run just e85 you could boost it until the block blew apart before detonation became an issue. In short lol