I have a 1994 NA 850, and live in Sao Paulo,Brazil. In my country, gasoline has a 25% ethanol content. My car is approaching 250K miles with no engine trouble.
Our ethanol comes from sugar cane. Cars made in Brazil are the flex fuel type.You can use gas or ethanol or a mixture of both. At the gas stations, ethanol is 45% the price of gas. Big difference. When driving a flex fuel car exclusively on ethanol, one gets better torque, but mileage drops by 20%.
Unfortunately sugar cane does not grow well in the US. In Brazil we get two crops a year and in the production of ethanol, some oil based products are used such as fertilizers and diesel oil for transportation. But in terms of energy balance, for every oil unit that goes in, 9 units of energy come out in ethanol. Also, the suggar cane bagasse is used as fuel in the suggar mills for electricity production. About 40% of electricity produced goes into the power grid, so the process is very efficient