With the EPA's recent decision to allow the use of gasoline with up to 15% ethanol (E15) in 2001 and newer model cars and trucks, Boat Owners Association of The United States (BoatUS) says that trailerboaters will need to remain extra vigilant when filling up their truck and trailered boat at the local gas station. That's because while E15 could be fine for the tow vehicle, it's not good - nor authorized by the EPA - for use with boats. A strong solvent, ethanol has been known to degrade marine fuel systems, damage engines, add safety concerns, and lead to expensive repair bills.
"When filling up at gas stations, boaters are used to pulling up to the pump and filling up the tow vehicle first, and then putting the same fuel nozzle into the boat," said BoatUS Director of Damage Avoidance Bob Adriance. "If that happens with E15, it could be a big mistake."
The EPA intends to put a warning on the pump - a small label with the exact wording yet to determined. "This is going to be a lot different from the choices offered to boaters today, where it's nearly impossible to misfuel gas or diesel engines, or where there are few consequences when choosing 87 octane over a higher 93 octane gasoline, for example," added Adriance.
All of this means that when E15 starts to appear in gasoline stations, boaters must heed the warning on the pump and shouldn't even think about using it in a boat. Here's why:
Going Lean isn't good: In addition to hydrogen and carbon found in regular gasoline, ethanol also contains oxygen, which means less air (or conversely, more fuel) is required for combustion. The term "enleanment" is used to describe what can happen when there is too much air and not enough fuel. While most cars and trucks on the road today have closed-loop systems that can adjust to prevent enleanment, most boats have open-loop systems which do not, adding a greater risk of heat-related damage to your boat's engine with E15.
Compatibility questions: Many components on a boat come in contact with ethanol-laden gasoline, including fuel lines, fuel tanks, fuel pumps, fuel injectors, carburetors, pressure regulators, valves, o-rings, and gaskets. The compatibility of these components with any blend greater than E10 is currently unknown. The failure of only one of these components in your engine could lead to failure or, worse, a fire or explosion.
A "good" thing isn't what it seems: Phase separation is what happens when gas becomes over-saturated with water, leading the water/ethanol mixture to separate from the gasoline and fall to the bottom of the tank (where the engine's fuel pickup is located). However, since ethanol absorbs water more readily than gasoline and it burns harmlessly through the engine, adding more ethanol to gas will decrease the chance for phase separation. You'd think that would be a good thing, right?
However, as you increase the amount of water in ethanol, this mixture also becomes more acidic, increasing the potential to corrode metal, including aluminum fuel tanks.
Also keep in mind that once gas has phase separated, the only remedy is to completely empty the tank. While BoatUS believes fuel additives in general are a good thing, it has not seen evidence of any additive being able to restore phase-separated gas back to its original state.
Your warrantee won't help you: Marine engines are only warranted for use with up to 10% (E10) ethanol.
For more information on ethanol, go to BoatUS.com/seaworthy/ethanol.asp. Or, to ask a question or see a discussion on where to find ethanol-free gas at marinas, go the BoatUS ethanol message board at http://my.BoatUS.com/forum.