I have been using ethanol 10% gas for years and have seen no ill effect,I think the biggest problem is it will turn bad in as little as three months and a lot of people wont run thru a tankfull in that amount of time.BTW a few years ago I had a problem with my 07 egc turned out to be ecm related dealer said sea foam was bad for fuel injected HD`s, when I told him I had used it thinking it would cure my poor idling he wanted to clean the gas tank first then they found the fix and went a different direction,but he was dead set against seafoam...