Standing Watch

EPA proposal to increase fuel blends to E15 concerns boat owners

Boating advocates warn the fuel blend is harmful to marine engines.

NATIONWIDE — Does ethanol affect your boat’s engine the same way corn syrup would your body? Recreational boating advocates and even the Environmental Protection Agency (EPA) have certainly warned high doses of the corn-based fuel is harmful to outboard engines, perhaps no different than corn syrup’s harmful effects on the human body when consumed in large quantities.

The EPA has proposed to increase the amount of ethanol blended into national gasoline supply for 2017, increasing the odds of E15 fuel being available to boaters across the country. Public comment was accepted on the proposal through July 11; it could be a while before the EPA makes a final decision.

Organizations such as BoatUS and the National Marine Merchants Association (NMMA) have been challenging the EPA’s recent ethanol mandates and urging boaters to demand fuel blends made available to them to contain no more than 10 percent ethanol.

In 2015 the Center for Regulatory Solutions published a report – “The Big Corn Sellout: How National Politics and Ethanol Mandates are Hurting California’s Economy” – stating the Renewable Fuel Standard (RFS), which launched in 2005, primarily benefits corn growers in the American Midwest.

“The policy forces billions of gallons of ethanol to be produced and mixed into gasoline each year, enriching corn-growing states in the Midwest at the expense of consumers, small businesses and farmers across the rest of the country,” the study, published in November 2015, stated. “The RFS survives because of power of the corn ethanol lobby in Congress, and because of the central role that Iowa – a corn-growing state – plays in presidential politics.”

Meanwhile Recreational Boaters of California (RBOC) recently campaigned for its members to demand the EPA establish a lower ethanol mandate. The RBOC campaign stated, “E15 has been proven to damage boat engines and so it is prohibited in marine engines.”

“If adopted, these proposed levels will require the use of a record amount of ethanol, forcing higher-level ethanol fuel blends (including E15 or 15 percent ethanol) into gas pumps and at more gas stations,” RBOC staff stated in its campaign to boaters. “Most marine engines are built to only work with up to 10 percent ethanol, and it is illegal to use gas containing more than 10 percent ethanol in any marine engine.”

There have also been attempts in the Senate to eliminate the ethanol mandate from the RFS. Sen. Dianne Feinstein (D-Calif.) and nine of her colleagues introduced the Corn Ethanol Mandate Elimination Act of 2013 to reduce how much ethanol is used in gasoline.

“Under the corn ethanol mandate in the RFS, roughly 44 percent of U.S. corn is diverted from food to fuel, pushing up the cost of food and animal feed and damaging the environment. Oil companies are also unable to blend more corn ethanol into gasoline without causing problems for automobiles, boats and other vehicles,” Feinstein said when she introduced the bill. “A corn ethanol mandate is simply bad policy.”

The bill, S. 1807, never moved beyond the introduction phase. Feinstein again introduced a similar bill in 2015 (S. 577), but, like S. 1807, the bill was not deliberated by the Senate.

The NMMA has actively campaigned against allowing E15 fuel blends to exist on the open market, claiming gasoline with 15 percent ethanol “is proven to damage marine engines and is a serious human safety, environmental, and technology concern.”

A one-page flyer issued by the NMMA outlined the interest group’s opposition to fuel blends of 15, 30 and 85 percent ethanol and explained boaters would likely be victims of misfueling if gas stations are permitted to allow E15 gasoline.

“For the first time in 2016, EPA has mandated ethanol volume levels that exceed the ‘blendwall,’ forcing an increase in the supply of E15. While EPA prohibits E15 for marine engines, it has taken no steps to educate consumers of the prohibition against and dangers of using E15, nor has it required that safe fuels (like E10 or E0) remain readily in the fuel supply.”

Fuels with more than 10 percent ethanol, according to NMMA, could result in diminished performance and stalling, engine corrosion, oil or fuel leaks, increased emissions, and damage to valves, rubber fuel lines and gaskets.

“The RFS is a broken law that sets unrealistic mandates, forcing E15 into the marketplace without consideration to its harmful effect,” NMMA said about the EPA ethanol mandate in its one-page flyer. “NMMA is not opposed to corn ethanol, but its widespread use has caused: engine failure at fuel ratios above 10 percent; land degradation from over farming, including nutrient enrichment of waterways; [and], higher food prices for feed and other food stuffs.”

Earlier this year BoatUS warned boaters of diminished supplied of E0 fuel to make way for E15 and higher blends as part of the EPA mandate and RFS.

“E0 (zero-ethanol) gasoline, which is sold at marinas and gas stations, is in effect being pushed out of boat fuel market to make room for the RFS-mandated E15 and higher ethanol blends. This means boaters may see shortages of E0 fuel as early as this summer’s boating season,” said BoatUS vice president of Public Affairs Scott Croft. “BoatUS believes boaters need a reliable, trusted fuel to ensure smooth engine operation and safe navigation.”

BoatUS President Margaret Bonds Podlich, in an opinion piece published in South Carolina newspapers in February, explained E15 and higher blends are damaging to marine engines because of phase separation.

“When gasoline containing ethanol and boats mix, boat owners lose. That’s because of something called ‘phase separation’ – think oil and vinegar – that can turn fuel stored in a boat’s gas tank into corrosive, water-soaked ethanol mixture, unusable in any engine,” Podlich stated. “The average cost for these repairs was $1,000.”

She added boaters prefer E0 but the national supply of ethanol-free gasoline was reduced from more than 8 billion gallons in 2014 to about 200 million gallons this year.

West Marine posted a warning on its website about possible E15 use, stating it is still unclear if or when the 15 percent blend would be available at local marinas but boaters should be vigilant in ensuring they pump nothing higher than E10 into their boats.

Complicating matters is what many believe will be an increase in gasoline prices should the ethanol mandate be expanded for 2017 and beyond.

An op-ed story published in the Kansas City Star on June 21 cited a Congressional Budget Office estimate that gasoline prices could jump 26 cents per gallon if ethanol volumes continue to be increased.

“About 90 percent of vehicles on the road today were not designed to use E15,” Ryan Rowden wrote in his Kansas City Star op-ed. “Extensive testing shows that E15 can cause damage to engines and fuel systems not covered by warranty. Higher ethanol content can also damage boats, classic cars, motorcycles, lawnmowers and power equipment.”

As the EPA deliberates the 2017 ethanol mandate there are a few people you can contact to ask questions or share opinions, including Feinstein, BoatUS and the NMMA.

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Standing Watch/Take Action

In this section you will find resources and supplemental information on what you can do to Take Action. Submit additional information or tips on this issue to

Take Action

Boaters can contact the EPA, NMMA or BoatUS for questions, concerns or comments about ethanol mandates and the RFS.

  • The EPA’s dedicated phone line for RFS questions and comments is 800-385-6164 and is active Monday- Friday, 9 a.m.-5 p.m. Eastern time.
  • Feinstein’s office can be reached at 202-224-3841, 310-914-7300 or 619-231-9712.
  • Michael Lewan of the NMMA is listed on the association’s anti-E15 flyer as the point of contact; his email is
  • Croft would be BoatUS’s contact; he can be reached at 703-461-2864 or