Marine Formula Fuel Stabilizer, 1-Gal.

What It Is

This is a 1-gallon container of marine-grade fuel stabilizer, designed to prevent fuel degradation and gum/varnish buildup in small engines used in boats, lawn mowers, trimmers, and other outdoor power equipment. It’s formulated for ethanol-blended fuels and extended storage (up to 12 months).

Fitment & Compatibility

• Machine types: Works with any 2- or 4-stroke small engine that uses gasoline—lawn mowers, tractors, zero-turns, chainsaws, leaf blowers, string trimmers, and outboard motors.
• Fuel types: Safe for ethanol (E10, E15), non-ethanol, and blended fuels. Not for diesel or mixed fuel systems requiring separate oil injection.
• Volume: 1 gallon treats up to 2,560 gallons of fuel (1 oz per 20 gallons). For a typical 5-gallon mower tank, you’ll use about 0.25 oz per fill—this bottle lasts years for home use.
• OEM vs aftermarket: No brand-specific fitment; universal chemistry. Compatible with all major brands (Honda, Briggs & Stratton, Kohler, Kawasaki, Toro, John Deere, etc.).
• Check before buying: Your storage duration (longer than 30 days? Use stabilizer). If you only run mowers seasonally, this is overkill—buy a smaller quart. Also verify your fuel is not diesel or pre-mix with oil injection.

Key Things to Know

• Quality: Marine-grade stabilizer has higher concentration of corrosion inhibitors and metal deactivators than standard automotive stabilizer, making it ideal for humid or saltwater environments. Overkill for dry garages.
• Installation difficulty: Extremely easy—just pour the recommended amount into your fuel tank or gas can before filling. No tools, no disassembly. Shake the can first.
• Common gotchas: Do not over-treat (follow ratio exactly—too much can foul plugs). Use within 2 years of purchase; stabilizer loses potency. Not a fix for old, gummy gas—stabilizer prevents, not cures.
• Storage: Keep the 1-gallon jug sealed and stored in a cool, dry place away from ignition sources. The large size is impractical for most homeowners unless you have multiple machines or a large fleet.

Should You Buy It

Buy this only if you have multiple small engines (mower, boat, generator, snowblower) and store fuel in bulk (e.g., 20+ gallons per season) or operate in a high-humidity coastal area. For a single mower used seasonally, a 1-pint or 1-quart bottle (around $10–$20) is more practical and avoids waste. This is a professional/enthusiast-grade purchase, not for casual home users.