The People of America's Oil and Natural Gas Indusry

Rising Ethanol Blends Don't Float All Boats

Mark Green

Mark Green
Posted October 24, 2013

Let’s continue discussion of the Renewable Fuel Standard (RFS), it’s detachment from market reality and its impacts on consumers – impacts that go well beyond the oil industry. Yesterday, we looked at the views of the National Chicken Council; today the view from the water, courtesy of the National Marine Manufacturers Association (NMMA):

With nearly 13 million registered boats (and nearly 16 million boats in the field) and 70 million boaters nationwide, the recreational marine industry is a major consumer goods and services industry that contributed $30.5 billion in new retail sales and services to the U.S. economy in 2009 and generates nearly 340,000 jobs nationwide. … NMMA strongly opposed – and continues to oppose – the granting of a “partial” or “conditional” waiver for E15 or any other ethanol blend level over ten percent ethanol (“E10”) because it will substantially increase public confusion and lead to persistent misfueling and consequent engine performance failures, emissions control failures, and consumer safety concerns. - NMMA Comments to the U.S. Environmental Protection Agency

The Department of Energy's National Renewable Energy Laboratory has tested the effects of E15 gasoline on some standard marine engines, and the majority of these engines suffered significant damage or exhibited poor engine runability, performance, and difficult starting – none of which is acceptable on a boat at sea. - NMMA Letter

E10 fuel has 3% oxygen while E15 fuel has 5%-6% oxygen. On a typical marine engine, this additional oxygen makes the fuel burn hotter, and the higher temperatures can reduce the strength of the metallic components. In addition, ethanol can cause compatibility issues with the other materials in the fuel systems because of the chemical interaction. -  David Hilbert, Mercury Marine

… we have determined that e15 blends of ethanol would cause considerable damage to the 7.5 million outboard engines in use in this country today. This damage is unnecessary and can be avoided by freezing the ethanol content of gasoline at 10% by volume. NMMA has never been anti-ethanol. We are simply opposed to fuel blends that will ruin our engines and place lives at risk. - Thomas J. Dammrich, President NMMA

All available evidence indicates that the introduction and use of E15 or any ethanol-blended gasoline above E10 will result in an increase in NOx (a smog-forming pollutant) emissions due to leaner operation, higher combustion temperatures, gumming and corrosion of fuel systems, and degradation to air emission control devices. All recreational marine engines and heavily regulated by EPA, and these engines are certified as compliant with air emissions regulations only up to E10. - NMMA Letter to the Illinois General Assembly

There is a significant amount of technical and anecdotal information that concludes that the introduction of E10 into the gasoline supply has caused significant damage and failure to boats. Although boat and engine manufacturers have adjusted and now design equipment to run on E10, the introduction of E15 will result in: (1) Damage to rubber parts; (2) water contamination in the fuel system due to ethanol’s hygroscopic properties; (3) increased water absorption and phase-separation of gasoline and water while in tank; (4) corrosion of fuel system components and fuel tanks; (5) higher exhaust gas temperature due to enleanment; (6) performance issues, such as drivability (i.e. starting, stalling, fuel vapor lock); (7) damage to valves, push rods, rubber fuel lines and gaskets. - Minnesota Testimony, NMMA

Currently, there are nearly 13 million registered recreational boats in operation in the U.S. No gasoline marine engine – or any other marine equipment including gasoline generators – currently  in the field was designed, calibrated, certified or is warranted to run on anything over 10 percent ethanol. EPA’s own “engineering judgment,” as well as all available data (supported by these two new studies), strongly suggests that all of the 12.8 million registered boats on the water today (with the exception of approximately 260,000 diesel-powered boats and the roughly 430,000 registered non-motorized craft) may be negatively impacted by any gasoline with more than a 10 percent ethanol blend. - NMMA Petition to EPA

The Renewable Fuels Standard must be revised to prevent the damage that ethanol blends above the 10% level will cause to engines of all types. … Unless the renewable fuels mandate is changed, it is likely that EPA would require 35%-40% ethanol in gasoline by the year 2022. Every time EPA changes the percentage of ethanol in gasoline, engines have to be recalibrated and engine designs changed. - NMMA Policy Brief


Mark Green joined API after a career in newspaper journalism, including 16 years as national editorial writer for The Oklahoman in the paper’s Washington bureau. Mark also was a reporter, copy editor and sports editor. He earned his journalism degree from the University of Oklahoma and master’s in journalism and public affairs from American University. He and his wife Pamela live in Occoquan, Va., where they enjoy their four grandchildren.