I grew up in Brazil, where we had a very successful program for cars running on ethanol fuel with a little gasoline added. It was common to have certain models of car be offered as gasoline or ethanol (back then engines needed to be tuned for one) powered.

At least one car magazine would buy retail cars and fully disassemble them for analysis a year later. The difference between a gas and an ethanol engine was quite shocking - the ethanol engine was always clean and displayed less wear than the gas version of the same engine. Part measurement indicated no significant difference in wear between the engines. There were models only offered with ethanol engines because they offered a little more power because of higher compression rate.