hahah Brian. There's numerous posts about being able to run 22+ timing and running 12.5 afr's or leaner with good results. As long as you have big injectors and a big fuel pump and a good way to tune. You can switch back to gas whenever your tank is low. If its your first time running e85 I'd recommend having fuel filter replaced after a tank. Depending on miles and state of your fuel system you might have to do that again, but I haven't had any problems on stock lines for 2-3 years now.