An important part of being a boat owner is maintaining it so it can function properly. It will also allow your boat to last longer. One way of maintaining your boat is by choosing the right fuel.

Gas Options

Current gasoline engines that are inboard, outboard, and sterndrive can operate safely with fuel that has, at most, 10% ethanol. This fuel is known as E10. Fuel that contains more than 10% ethanol should not be used in a boat. Doing so can void the warranty on your boat.

The Best Fuel

Boat engines cannot tolerate an ethanol blend that is over 10% because it can be corrosive to the engine. If you have an older boat with an older engine, you may not be able to use fuel that contains ethanol. 

You cannot use the fuel because these boats were not designed to tolerate it. If you want to use ethanol fuel in your older boat, you will have to update the system. To check which fuel your boat can take, look at the fuel pump labels. E15 is growing in popularity throughout the country.

Downsides to Ethanol

If you can avoid ethanol, then do so. Due to the fact that water is attracted to ethanol, moisture can get into the fuel tank vent system. The engine can become inoperable as a result of phase separation. 

Phase separation is when water mixes with gasoline, and the ethanol attaches to the water molecules, creating two layers in the tank with gasoline on the top and the water mixed with ethanol on the bottom.

Keeping Water Out of the Fuel Tank

If you check your owner's manual, you should see a minimum fuel octane rating. You may find that high-performance engines have a higher octane rating. Using a water-separating fuel filter can keep water out of the engine by placing it between the fuel tank and engine. 

You can find out from your engine manufacturer the right filter for your boat. Having a spare filter on board will spare you a lot of trouble. Adding the correct ratio of boat fuel stabilizer in the fuel tank can stop oxidation and phase separation from happening.

When choosing a fuel for your boat, you want to make sure you select the right one. You should use gasoline that has 10% or less ethanol. Older boats may not be able to use fuel that contains ethanol. It is also important to keep water out of your fuel tank. 

We hope you found this guide helpful! If you have any questions about fueling your boat, we invite you to consult the team here at Bay Outboard Marine. We’re proud to be your local boat dealership in Saginaw, MI, serving those in Bay City, Midland, and the surrounding areas.