Two-Stroke Mix Ratio Check

The gas:oil ratio you ACTUALLY made from the oil you poured.

Run the calculator

Example

You enter

You get

Details, formula, and sources

ratio = fuel volume / oil volume, flagged against a target. 2.56 oz in a gallon is 50:1; 3.2 oz is 40:1 (richer). A LEAN mix (higher X:1, too little oil) starves the bearings and risks seizure - the dangerous error; a RICH mix (lower X:1) smokes and fouls but protects the engine. First-principles volume arithmetic; the equipment manual's ratio governs.

ratio = fuel volume / oil volume (same units; 1 US gallon = 128 fl oz); oz per gallon = 128 / ratio; verdict vs the target ratio.

Two-stroke fuel/oil mix ratio check by volume, the inverse of the mix tile; first-principles volume arithmetic, public domain. The oil grade and ratio are set by the equipment manufacturer.

Pure arithmetic, public; modern air-cooled two-strokes are commonly 50:1 with a JASO/ISO oil, but the equipment manual governs.

Estimate. AHJ and licensed professional govern.

Field names used by the API: fuel_amount, fuel_unit, oil_amount, target_ratio, ratio, oz_per_gallon

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