This site helps you find (and avoid) petrol stations selling E-15.
http://www.ethanolretailer.com/flex-fuel-station-finder
Snopes has an entry about E-15.
http://www.snopes.com/politics/gasoline/e15.asp
What to know about the E-15 gas blend (they downplay its problems)
http://www.myfoxtwincities.com/story/23824572/what-to-know-about-the-e-15-gas-blend-debut
The only reason E-15 was brought to market was a powerful Washington lobby for it why I don’t care to use it. If there was some real reason why it’s better then I’ll listen.