There is one important aspect of different fuels (gasoline, ethanol and methanol) mentioned by av8tor1977. It is a fuel to air mix. Engine takes over 50% more E85l (by volume) compared to gas so the mileage of E85/glow mix is much worse than gas/glow mix. E85 gets a little more power but the amount E85 of fuel to produce the equivalent power to gasoline is still much higher. With E85 price only just a bit lower than gasoline it is something to think about before switching your car to FFV model.

The only one benefit of using E85 in our gas-glow conversion is that E85 is burning at lower temperature so it might be gentler to glow plugs. Other than that I don't see any reason to use E85. If you want more power then mix more methanol, less gas.