I always thought that E85 was a less energy dense fuel. It does have a higher octane rating and it does have lower tail pipe emissions. but what benefit would you have? most regular fuels can have up to 10% ethanol anyway (I think recent law passed that made it so if its under 10% they did not need to advertise that it had that % in it...)
So your raising the octane of the fuel in your tank but your also lowering the energy density also. you may see a small drop in MPG. I think most flex fuel vehicles get a way with a slightly higher compression (due to E85 having a higher octane rating) to make up in their power.
I think a report showed that the Escalade vs the E85 and the normal one had a 1-2 MPG difference in its fuel economy. but E85 is sometimes cheaper and has less of a carbon footprint.
2001 ZX3 2.0L Zetec-
Hatch Nation #42
Going through Rebuild See "The TICK Build Thread" for details (http://www.focusfanatics.com/forum/showthread.php?t=289168&referrerid=62897)