Don’t guess the hose
E15 is not for boats
If the sticker says 15% ethanol, walk away. That hose stays Call. Ethanol is what the sticker says, not what the octane implies. Octane is not a test for ethanol.
E15 walk away. E10 runs. E0 sits better. Call if unlabeled.
The hose that damages an outboard
E15 is gasoline with 15% ethanol. EPA lists boats with snowmobiles and other nonroad engines as equipment that must not use it. NMMA says the same. Most warranties stop at E10.
In March 2026 EPA widened E15 on the highway for the summer driving season. That waiver is for cars. It does not put E15 in a Yamaha or a Mercury. More green stickers at the ramp raise the odds a trailered boat gets the wrong hose.
E10 runs. E0 sits better.
E10 is what most late-model outboards are built to take. It still pulls water. A tank that sits between weekends is happier on ethanol-free — E0, sometimes sold as Rec-90 — when the dock has it.
When a dock has E0, the card says E0. When the public page said non-ethanol: no, we mark E10. If nobody labeled the pump, the blend stays Call. Octane is not a test for ethanol.
What to do
- Read the pump sticker. Walk away from E15.
- If the card says Call — call the dock.
- Ask whether the high-octane hose is E0 or just 93 with ethanol.
- Then post what you saw so the next boat is not guessing.