theyre relatively inexpensive, and specifically labeled for use in ethanol-added gasoline.. i know crc makes some thats sold at academy for about three bucks a bottle. treats numerous tankfuls. the summer will see an increase in ethanol added fuels. YOU MUST KEEP THAT ETHANOL FROM SEPARATING…either thru regular replacement of gas (aka..use) or thru additives. once separation happens, youre looking for trouble. also..not even mentioned in the article, is the RUST problems mechanics are starting to see inside the engine from the moisture problems the ethanol creates. its just not a good thing for boaters, but we may not have a choice in the matter. TIME TO FEED THAT DARN CORN TO THE COWS AGAIN!