I have to disagree with most of the claims in the article by Robert Bryce of Slate that appeared in the Sunday 8-5-12 “Trib” of Waco, Texas, USA. There was too much anti-biofuel propaganda in it, stuff I know from experiment to be false.
The one thing I do agree with is that ethanol (or any other biofuel) should not be produced from food crops, because this immediately puts you into the food vs fuel dilemma. There are other feedstocks for all the biofuels, and these should be encouraged.
The best way to do this is reduce subsidies for food crop biofuels, but increase subsidies for non-food crop biofuels. Ethanol can be made from cellulose, and from grocery store spoiled fruits and vegetables no longer suitable for food or feed. Those last go to the landfills by law in most states, and that needs changing.
Most of the lawn and garden equipment, and most of the older cars, were intended to run on straight gasoline, not even an E-10 gasohol. Yet they all work just fine, completely unmodified, on E-10. This includes boat motors and 2-stroke equipment. Everybody is already doing it, that's what "gasoline" is now: E-10.
Most of the troubles I have heard about trace to bad housekeeping, not any “corrosive” properties of the fuel. Susceptible materials pretty well disappeared with the advent of unleaded gasoline about 1970. Pre-existing dirt and water get suddenly mobilized upon switching to E-10 (or any other) gasohol.
That dirt plugs carburetor orifices, and too much “water bottoms” in the tank will separate-out as a wet ethanol layer that the engine cannot burn. The “fix” is easy: drain and flush the fuel system and clean the carburetor. You do not have to overhaul the engine, that is a lie used by the unscrupulous to over-charge you.
I have not tested gasohols stiffer than E-10 in my 2-stroke equipment, so I cannot yet recommend greater-than-E-10 for engines like that. But I have had no problems in my 2-stroke equipment with the E-10 that is gasoline today.
The anti-ethanol lobbies have convinced the EPA that E-15 might damage catalytic converters in cars older than 2000 models. The experimental truth is quite the opposite: using gasohols from E-15 to E-35 actually cleans soot out of your exhaust components, including the catalytic converter. Soot clogging is usually why catalytic converters “die”.
I have used E-25 to E-42 gasohols, most commonly E-30 to E-35, very successfully for 6 years now, in a variety of completely-unmodified vehicles and 4-stroke lawn and garden equipment, some of it 50 years old. I have not seen one single problem caused by the fuel, and I have data to prove that vehicle mileage is the same as straight gasoline up to about E-42. There are minor winter cold start glitches above E-35: it often dies at cold idle, and you have to start it again.
I have two vehicles that I converted to run on E-85 mostly-ethanol fuel, one of them over 60 years old. Both ran better on ethanol than they ever did on gasoline: cleaner and more powerful. Mileage was down, but not as far as you would expect from the fuel energy per gallon. I never saw one fuel-related “corrosion” problem in either one. In fact, the 60-year-old rusty gas tank is mostly now cleaned of corrosion. In other words, corrosion-wise, things got better, not worse, with ethanol.
If you want to try a stiff gasohol for yourself, then use no more than 1/3 E-85 with 2/3 gasoline (at 10% ethanol these days). That 1/3-2/3 mix is an E-35 blend. It’s a drop-in fuel, no modifications needed at all. To check mileage effects, you need to average dozens of tanks for each fuel , because the natural scatter in your data is very much larger than any effect you would ever see.