That's what I do is buy ethanol free gas, there's only a couple stations in the area that sell it though. As far as the marine stabil/ seafoam additive, I actually use about an ounce of each one in every 6 gal. of gas I put in my boat. I had my oiler unhooked and mix my gas and oil myself so I just put it right in when mixing it. Haven't had any issues.