Ethanol fuel will only cause an issue if your fuel system is dirty to begin with. Tha alcohol is a serious cleaner and loosens any crud it comes in contact with. You should run a fuel conditioner at all times to keep the system clean, even with ethenol free fuels!! I cleaned my fuel system and converted the hoses on my 1983 boat engine, been running 10% for almost ten years with no issues. My neighbor is an engine mechanic, never saw a real problem with ethanol fuel as long as system is clean to start and kept clean!!!