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Fuel and oil mix calculator ?

Choose petrol or turbine, enter how much fuel you're mixing and the ratio or percentage from your engine's manual. The calculator gives the oil to add.

The amount of petrol before you add the oil.
Enter 40 for 1:40, 50 for 1:50. Running in usually takes a richer mix - check the manual.

Result

Fill in the numbers above to see the result.

How it works

A ratio of 1:40 means 1 part oil to 40 parts petrol, so the oil = petrol ÷ 40. Five litres at 1:40 needs 5000 ÷ 40 = 125 ml of oil.

The oil share of the finished mix is 1 ÷ (ratio + 1) - about 2.4% at 1:40.

Turbines: makers give a percentage of the fuel, so 5% means 5 ml of turbine oil for every 100 ml of kerosene - 50 ml a litre, 500 ml in a 10-litre can. That's the same as a 1:20 ratio, and the oil ends up about 4.8% of the finished mix.

Use a good two-stroke oil made for air-cooled engines (or the turbine oil your engine maker names), shake the can before each fill-up, and don't keep mixed fuel for months - it goes stale.

Keep every model's numbers in one place RC Flyer Pro is a free logbook and hangar for RC pilots: your models, batteries, flights and flying field, with GPS flight replays in 3D. Start free

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