Last week, the Trump administration announced that it wants to allow the year-round sale of 15 percent ethanol blended fuel, or E15. Numerous groups oppose the initiative, including the National Marine Manufacturers Association (NMMA) and BoatUS.
Ethanol blended fuels cause problems for marine engines of all types, especially outboards. Until now, E15 was not being sold during the summer when most of those engines are generally used. E10, which has 10 percent ethanol content, and has also been associated with engine problems, can be sold during the summer. Ethanol has shown a corrosive effect, especially on rubber parts, like gaskets and hoses, and in particular on older engines. Ethanol-blended gasoline can also undergo phase separation in fuel tanks, which leaves behind a gooey residue that can foul fuel systems.
BoatUS, NMMA and other groups are concerned that owners will inadvertently fill their tanks with E15 and they vowed to continue to oppose its year-round sale.