Ethanol’s Worst Enemy

Alcohol has the power to ruin lives if you let it. It also has the power to wreak havoc on a boat’s fuel system.

If you need a bit of background, ethanol is used to “oxygenate”  fuel to help reduce hydrocarbon emissions that cause air pollution. Of course, the best alcohol is derived from malted barley and comes in a bottle marked “Product of Scotland,” but alcohol used for ethanol can be made from cellulosic materials such as corn stalks, grain straw, paper, pulp, wood chips, municipal waste, switchgrass, and other sources.

Volvo-Penta's new treatment should be a potent ally in the war against water in marine fuel.
Volvo-Penta’s new treatment should be a potent ally in the war against water in marine fuel.

The major problem with ethanol, particularly for marine engines that sit long between uses, is that ethanol oxidizes and can absorb water. That can cause corrosion. For example, E10 can hold approximately one half of one percent water at 60° Fahrenheit. At lower temperatures, such as 20 degrees Fahrenheit, E10 can hold less, about 0.35% water, which still means 0.45 ounces in a gallon.

So when I learned that Volvo Penta had introduced a new fuel additive to protect marine engines from the harmful effects of ethanol, I took notice. Suitable for any outboard or sterndrive system, Volvo Penta recommends using it every time you fill up with ethanol-blended gas to protect your engine from damage.

“Ethanol-blended fuels such as E10 and E15 are approved by the U.S. Environmental Protection Agency for the automotive market, but ethanol damages marine engines and fuel systems due to the corrosive properties of alcohol,” explained David Kennedy, director of parts and accessory operations for Volvo Penta of the Americas. “Unlike automobiles, most marine engines are only operated intermittently. Today’s oxygenated and ethanol-blended fuels can begin to oxidize in as little as 30 days if left untreated in the boat’s tank, resulting in corrosion inside the engine and fuel system.”

Formulated with antioxidants to combat fuel breakdown, the new fuel treatment also contains chemical corrosion inhibitors that form a protective barrier on fuel system components. For some reason, Volvo Penta points out that it contains no alcohol. Well, duh. What caught my eye is that 12 ounces treats up to 60 gallons of fuel and keeps fuel fresh for up to one year.

If I were to take delivery of a used boat, this new fuel treatment likely would be one of the first things I would put on my shopping list.