Mercury Marine has joined other boat-motor manufacturers in stressing that marine engines should not be powered by E15, which is gasoline that contains 15 percent ethanol.

The blended fuel, which is available at a limited number of gas stations in Minnesota, is “extremely harmful to marine engines,” Mercury said in a recent announcement.

Most gasoline sold in Minnesota contains 10 percent ethanol. The E15 blend has been available at a handful of stations since last fall, and Mercury Marine, along with the National Marine Manufacturers Association (NMMA) and the Outdoor Power Equipment Institute (OPEI), are concerned that consumers don’t pay careful attention when purchasing gasoline and might buy fuel for small engines and boats that will harm the equipment and void warranties.

“We will continue to fight against E15 in marine engines and know the OPEI and NMMA will do the same. We need to get this message in the hands of every boater before they fill up because if they don’t know, they could damage their engine,” Mercury Marine vice president Marty Bass said. “Most of these failures don’t occur at the dock, but rather while you are on the water, which then becomes much more dangerous.”

The Environmental Protection Agency has approved gasoline with 15 percent ethanol for use in cars year 2001 or newer. But its use is prohibited in mowers and other power equipment, stating it might cause damage.

On its website, Yamaha outboards cites a Department of Energy study that “found that E15 caused hotter operating temperatures, erratic running, and engine-part failure,” adding, “but even gas with the usual 10 percent ethanol [E10] could help destroy small engines.”

Yamaha goes on to advise: “If at all possible, do not use E10 fuel.”

Fuel stabilizers such as Sta-Bil can mitigate possible problems with E10, Yamaha says, but notes: “Stabilizers do not help fuel that has already aged. Stabilizers are most effective when immediately added to fuel fresh from the gas station or marina fuel pump.”

In the end, if possible, it’s best to use nonoxygenated gas in boat motors, manufacturers say, as well as in lawn mowers and other power equipment.

Various websites online list gas stations in Minnesota that sell ethanol-free gas, and some sites provide maps of their locations.

One website with such a list is Also noted on the site are stations across the U.S. and Canada that sell ethanol-free gas.


Dennis Anderson