You would get way better mileage and way more power if you set up the engines to run on ethanol instead of gas. All the flex fuel engines have been designed to run on gas and than they change the fuel mixtures to run on E-85. If the engines were set up to run on ethanol originally they could do away with a lot of the pollution control features on the engine because ethanol burns so much cleaner and doesn't have a pollution problem. They would also run a lot high compression as ethanol is very high in octane and a high compression engine needs high octane to run efficiently. There are not as many btu's in ethanol but it is a lot better fuel that could be used a lot more efficiently. I think it is unfortunate that we don't blend ethanol in the diesel fuel. If we used an ethanol blend in diesel fuel it would improve both the mileage and power and the engine would also run cooler.