FAQ

Asked at the pump

Does a fuel stabilizer actually do anything?

In third-party ASTM testing, yes, measurably: untreated E10 fuel went unstable at 240 minutes in the D525 oxidation test, while the same fuel treated with Ethanol Shield held past 1,500 minutes — better than six times the stability. The corrosion panels tell the same story, with the top 1a copper-strip grade and the highest NACE rating for ferrous metals.

How much do I pour?

The everyday dose is 1 oz per 2.5 gallons for small engines, 1 oz per 10 gallons in a car or truck, and 1 oz per 5 gallons with the marine blend. For storage — the last tank of the season — go to 1 oz per gallon and run the engine a few minutes so treated fuel fills the lines and carburetor.

Gasoline or marine — which bottle?

Both stabilize, clean and fight corrosion. The marine formula doubles the antioxidants and triples the anticorrosive package because boat tanks sit longer and live over water. If the machine floats, or winters somewhere damp, take the marine bottle; for the mower wall and the gas cans, the standard one is the one the OEMs test.

Will it fix fuel that already went bad?

A stabilizer preserves, it does not resurrect. If a machine is already gummed up and cranky from last year's fuel, that is the job of the kit on our shelves — Mechanic In A Bottle cleans out varnish and carbon, and the stabilizer keeps the fresh fuel honest afterwards.

Does it work in 2-cycle premix?

Yes — the formula covers all 2- and 4-cycle engines and also helps bond the oil to the gasoline-ethanol blend, which keeps premix consistent in storage.

What about diesel?

The stabilizer line on these shelves is for gasoline. In the combo kit, Mechanic In A Bottle carries a gas-and-diesel formula — that is the bottle in this catalog that touches diesel tanks.

How long does treated fuel stay good?

Up to three years, per the maker's testing — long enough that the snowblower can skip a mild winter and still start on the fuel it parked with.

Why do prices here sometimes differ from the storefront?

Our pages show a snapshot; the partner storefront sets the live number. The stamp on any product page takes you to today's price.