[JamesP81]

At the plant I used to work at, a guy used to run his car on 85%, with no modifications. Ran ok, but the timing was certainly off.

It seems to me that switching out the computer chip and adding a fuel tank sensor to detect the mixture is all you would really need then to make it a viable design.

[redgolum]

Probably would. Most newer cars from Ford and GM can run higher percentages of ethanol than you see at the pump. The oxygen sensor will adjust the timing for it.