HomeNewsNMMA Offers Ethanol Protection Tips Boaters know that using fuel with a volume of ethanol above 10 percent can seriously damage marine engines. But did you know that unused fuel can linger in your engine during the winter months, causing additional problems? There are a number of ways to prevent engine damage when storing boats with ethanol-blended fuels for extended periods. Read on for a few tips and recommendations on keeping your vessel’s engine in prime condition from year to year. • First, never fill your boat’s tank with fuel that is above 10 percent ethanol in volume. There are serious and well-documented human safety, environmental, and technology concerns associated with ethanol blends over 10 percent in recreational boat fuel tanks and engines • Check the owner’s manual of your boat and motor(s) for manufacturer’s storage recommendations. • When preparing to store a boat for extended periods of two months or more, it is best to completely remove all fuel from the tank. • If it is difficult or not possible to remove the fuel, maintaining a full tank of fuel with a fuel stabilizer added to provide fuel stability and corrosion protection is recommended. • Fill your fuel tank to avoid a buildup of condensation over the winter months. Add a fuel stabilizer by following the instructions on the product. Change the fuel filter and water separator. • If adding stabilizer, it is best to add the stabilizer and fuel treatment to the tank at the recommended dosage; shut off the fuel valve to interrupt the fuel supply and allow the engine to run until it stops; top off the tank until it’s full to reduce the amount of exchange with the air that might bring in condensation. • Do not cap the tank vent and do not fill with fuel to the point of overflowing. Some extra space should be maintained in the tank to allow for expansion and contraction of the fuel with temperature changes. • When placing the boat back in service, be sure to reopen the fuel valve to the engine. For a complete list of steps to take for winterizing your boat, visit Discover Boating, here. For more information on high ethanol fuel and the damaging effects to marine engines visit www.SmarterFuelFuture.org or www.NMMA.org.