Three Best Fuel Additives for Boats

The best fuel treatment choices for winterizing your boat.

October 27, 2021
Fuel additives for marine engines
Additives can keep your fuel system in top condition. Courtesy Techron/Chevron, USA Fuel Service, Gold Eagle

Everyone tells you to use a fuel conditioner, especially when running ethanol-laced fuels in your engine. It’s common knowledge that treating your fuel can help keep it fresh when it sits for long periods of time. But with so many on the market, which one should you choose? We review three of the top performers to help you narrow it down.

Techron Protection Plus Marine Fuel System Treatment

Pros: Techron’s alcohol-free formula does not contribute to water absorption in the fuel, helping to minimize corrosion damage caused by water separation in the fuel system. Its detergency removes and prevents deposits on valves and piston tops, and also prevents gumming and varnishing in the fuel system. Reportedly, its formula stabilizes fuel for up to 24 months. It can also treat diesel fuels. It’s available at many larger online and brick-and-mortar big-box retailers, and the pricing is competitive.

Cons: Might not be available at local marine suppliers.


Price: $10.49 for an 8-ounce bottle;

Gas-Shok Plus Water Absorber & Fuel Stabilizer

Pros: Gas-Shok advertises that it controls and disperses water in boat fuel tanks and systems, protects rubber and plastic seals and gaskets from ethanol damage, restores lost fuel economy due to carbon-fouled rings, valves and injectors, stabilizes all gasoline blends, including ethanol blends, and adds lubrication to extend fuel-pump and injector life. Gas-Shok is available locally and works well to ward off fuel degradation when used regularly.

Cons: Might not be available for sale in your local market unless a dealer network is active and aggressive.


Price: $18.85 for 8-ounce bottle;

Sta-Bil Storage

Pros: Sta-Bil Storage fuel stabilizer is widely distributed and offered nearly everywhere and has been available for decades. Dubbed “America’s most trusted fuel additive,” Sta-Bil Marine is said to be engineered to combat the effects of harsh marine climates, providing defense against the harmful effects of ethanol-blended fuels with industry-leading water-removal properties. Sta-Bil is advertised to keep fuel fresh for up to 12 months. Available at most marine dealerships and big-box retailers, with a competitive price.

Cons: Shorter advertised fuel life than some brands (12 months vs. 24).


Price: $8.98 for 8-ounce bottle;


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