This is not heresay. There was an article in ?Landscape Digest? (a Moose River mag) where they were discussing the threat of 15% ethanol. It was in that article where a guy down in the south had been testing ethanol fuel for years - and found wildly erratic percentages (from 5-20%). I'm too lazy to look up the article, but that really struck me when I read it and I've retained it since.