Why do some mechanics say not to use ethanol?
A mechanic who says not to use ethanol does not have correct information. About the only thing most people (including many mechanics) know about gasoline is that some of it is blended with ethanol. When there appears to be a fuel-related problem with an engine, some mechanics will immediately ask if ethanol has been used. One reason ethanol is suspected is that in many jurisdictions it is the only gasoline component that requires an identifying label.