Aside from regular, mid-range, and premium a new ethanol blend, E15 is finding its way into gas pumps and boaters are being warned with bright orange labels.
Mechanics advise avoiding standard E10 or using additives if only ethanol is available and not letting ethanol sit in tanks for more than two weeks. Ethanol, E10, contains alcohol which is “hygroscopic,” meaning it attracts water molecules. Boat fuel systems are vented, and moisture collects in fuel and bonds with alcohol, sinking to the tank bottom where fuel pick-ups are located. At this point nothing good happens from performance issues to catastrophic engine damage as the powerful alcohol astringent loosens fuel tank debris.
E15, with even more alcohol, is showing up unannounced at pumps across the country and is not approved in outboard motors by every manufacturer. Boat Owners Association of The United States (BoatUS) reminds boaters to ensure the right fuel goes into the tank since fuel sellers don’t make the clarification between mixtures. Federal law prohibits using E15 fuel in boats. Ethanol voids engine warranties and has been proven to cause damage to marine engines. Any pump dispensing E15 fuel must have an approved orange warning label.
Major engine manufactures include E15 fuel tank warning labels. Warranty coverage on a wide range of repairs and services are voided on Mercury engines operated using fuel with an ethanol content of more than 10%. It’s been Mercury’s long standing policy for years that ethanol can damage outboards, but the availability of E15 at pumps this summer adds more risk of its use.
This could be due to an unaware boater or one who wants to save money and isn’t aware of the damage ethanol can cause. But it’s endangering boaters who know, but might not notice the pump’s ethanol-content labels when fueling up.
More E15 is available as a Clean Air Act waiver expanded the sale to June 1 to September 15, prime boating season, where it had previously been excluded. BoatUS has fought efforts to weaken pump labeling rules, maintaining pressure to keep bright orange labels and to educate boaters about E15 hazards to boats.
Another major outboard manufacturer, Yamaha, recommends a ten-micron water-separating fuel filter. Yamaha also recommends a marine-specific fuel stabilizer and conditioner every fill up to prevent oxidation and phase separation to protect metals from the destructive sodium sulfate present in ethanol.
Purchasing fuel from a high volume station will provide the freshest gas possible since ethanol-blended gasoline has an extremely short life. If using a boat infrequently, mechanics recommend keeping tank fuel levels at 7/8 full of properly stabilized fresh gas to prevent condensation buildup in the tank.
No matter how eager you’re to get out on the water, slow down at the gas pump and read ethanol-content labels, being sure to use only gasoline with ethanol content of 10% or less. Many astute boat owners use only ethanol free fuel to avoid major issues with E10, while keeping a watchful eye on pumps with E15 orange labels.
Author Capt. Steve Chaconas is Potomac bass fishing guide & freelance writer. Potomac River reports: www,nationalbass.com. YouTube video channel NationalBassGuide.