There is a HUGE difference between E85 and E10. We've been using and tuning E85 for a while now. We're starting to use and tune E100 also. If you use the E85 be aware you're going to have to do a lot more tuning both with fuel and ignition but mainly fuel. Ontop of that it requires on average 25% - 35% more fuel ontop of 93 octane fuel values. We've made some very good power on both E85 and E100