Premix Chart
2-Stroke gas / oil mix reference
Common ratios at a glance — millilitres per litre, fluid ounces per gallon.
| Ratio | Oil (ml) per 1 L of fuel | Oil (fl oz) per 1 US gal | Open calculator |
|---|---|---|---|
| 16:1 | 62.5 | 8.0 | → |
| 20:1 | 50.0 | 6.4 | → |
| 25:1 | 40.0 | 5.1 | → |
| 32:1 | 31.3 | 4.0 | → |
| 40:1 | 25.0 | 3.2 | → |
| 50:1 | 20.0 | 2.6 | → |
| 60:1 | 16.7 | 2.1 | → |
| 80:1 | 12.5 | 1.6 | → |
| 100:1 | 10.0 | 1.3 | → |
How to read this 2-stroke premix chart
Every row shows one mix ratio, paired with the oil amount per 1 litre of fuel and per 1 US gallon of fuel. Find the ratio your engine wants, then multiply by your jerry-can size. A 10 L can at 50:1 needs 10 × 20 ml = 200 ml of oil; a 2.5 US gal can at 40:1 needs 2.5 × 3.2 fl oz = 8 fl oz. For odd volumes the arrow on the right of each row opens the calculator pre-filled with that ratio.
Why the right premix ratio matters
Two-stroke oil does three jobs at once: it lubricates the crank bearings and small-end, it seals the rings against the cylinder, and it carries heat away from the piston crown. Too little oil and the piston runs dry, the rings glaze, and you lose a top-end. Too much oil and combustion gets dirty — fouled plugs, sticky power valves, a smoky exhaust, and slowly dropping compression. Sticking to the manufacturer's specified ratio (with an oil that actually meets the JASO FD or ISO-L-EGD rating) is the single cheapest way to extend a 2-stroke engine's life.
Picking the right premix oil
- Full-synthetic JASO FD / ISO-L-EGD: The benchmark for modern enduro and motocross 2-strokes — Motorex Cross Power 2T, Motul 800 2T, Maxima Castor 927, Bel-Ray Si-7. Safe down to 60:1 on TPI/i bikes that specify it.
- Semi-synthetic premix: Good general-purpose oils — Motul 710 2T, Motorex Power Synt 2T, Castrol Power 1 Racing 2T. Run them at the ratio printed on the bottle (usually 50:1 or 40:1).
- Mineral / castor blends: Castor blends (Maxima 927, Klotz BeNOL) are race-only — incredible film strength, but they leave residue and have a short shelf life once mixed. Don't use them in a trail bike.
Premix chart — frequently asked questions
How many ml of oil per litre at 50:1, 40:1 and 32:1?
50:1 needs 20 ml of oil per 1 L of fuel. 40:1 needs 25 ml per 1 L. 32:1 needs about 31 ml per 1 L. The chart above lists every common ratio from 16:1 to 100:1.
How many fl oz of oil per US gallon at 50:1?
At 50:1 you add 2.6 fl oz of oil per 1 US gallon of fuel. The chart shows the fl oz / gallon value for every other common ratio too.
Which premix ratio should I use on a KTM, Husqvarna or GasGas enduro 2-stroke?
60:1 if you run the factory Motorex Cross Power 2T oil that ships with the bike. 50:1 with most other quality JASO FD / ISO-L-EGD premix oils. Always check the owner's manual for your specific year and model.
Is 32:1 better than 50:1?
Not for modern enduro 2-strokes — running 32:1 on a bike designed for 50:1 just fouls plugs, gums up the power valve, and smokes more. 32:1 is the right ratio for older race 2-strokes (Yamaha YZ, Honda CR, vintage MX) where the engine was designed around that mix. Run what the manual says.