After asking questions here and doing the math I decided not to do it.

My motor is just 11.5:1 with good quench so I can get by mixing 3 gal. of 94 octane with 2 gal. of 110. When I figured in the 40% to 50% increased volume of E85 needed the savings were very little to non existant.

The added problems of it not being available at the track and inconsistant grades of E85 (E70 to E90 and anywhere in between)made me decide against the switch.