All I know is I buy 100% gasoline for the scooters and lawnmowers I have. And the pickup since I rarely have to fill it up. I've fixed more than a few lawnmowers with problems of water absorption and settling out in the bottom of the gas tank. So with ethanol you have water problems develop and it may or may not deteriorate plastic and rubber seals and gaskets in the fuel systems.
Further reading ...
http://www.hho4free.com/gasoline_vs_ethanol.html