But 10 years of burning "E10" (10% ethanol, 90% gasoline) in our boats, we've suffered through rough running, clogged fuel filters, poor fuel mileage, damaged fuel lines, leaking tanks (including some brand-new "ethanol-resistant" models), and catastrophic engine failures, with higher food prices as an added insult. As a fuel additive, ethanol offers only 65% of the energy content of gasoline, it attracts and readily mixes with water (a good attribute in whiskey but not in boat fuel), it corrodes metals, and it is has high vapor pressure, which actually helps fuel sitting in tanks evaporate and damage air quality. What's to like here? Not much!