I am not taking up for ethanol and I fully believe that mpg goes down when using it, after all ethanol has much less energy content than gasoline. Just Google it for links.
What I question is if it actually causes damage. This thread is full of reports about tests or experiences but I don't see many links to an actual published report. About the only one is a Honda link and they say that 10% is OK.
Can anyone give a link to the reports from Mercury or any other or do we just take the poster's word for it.
This is a wonderful forum but it would be so much more so if posters provided documentation or at least said that it was only their opinion.