They will run on E-85, but if your vehicle wasn't built for it then it will start to corrode parts in your engine, since it is alcohol. Also you should run a mixture of gas, and E-85 if your vehicle wasn;t meant to run on it, E-85 has an octane rating of 105, so if you add gas you will bring that down to what your vehicle should run on. <img src="/forums/images/graemlins/cheers.gif" alt="" />