If you have a two-stroke engine, such as a chainsaw, trimmer, off-road motorcycle, or marine engine, it is important to know the correct fuel-to-oil ratio. Using the wrong ratio can result in reduced performance, engine damage, or even failure. One of the most common ratios is 30:1, which provides adequate lubrication for modern two-stroke engines.
What is a 30:1 Fuel Ratio?
A 30:1 fuel ratio means 30 parts gasoline to 1 part 2-stroke engine oil. For example:
- 1 litre of gasoline → 33 mL of oil
- 1 gallon of gasoline → 4 fl oz of oil
This mixture ensures proper engine lubrication, reduces carbon deposits, and keeps your engine running smoothly.
30:1 Fuel Mix Chart (Metric + U.S. Customary)
| Fuel (Liters) | Oil (mL) | Fuel (Gallons) | Oil (fl oz) |
| 1 | 33 | 1 | 4 |
| 2 | 67 | 1.5 | 6 |
| 3 | 100 | 2 | 9 |
| 4 | 133 | 2.5 | 11 |
| 5 | 167 | 3 | 13 |
| 7.5 | 250 | 4 | 17 |
| 10 | 333 | 5 | 21 |
| 15 | 500 | 7.5 | 32 |
| 20 | 667 | 10 | 43 |
| 25 | 833 | 15 | 64 |
How to Mix a 30:1 Fuel/Oil Ratio.
- Measure the gasoline: Pour the required amount into a clean container.
- Add two-stroke oil: Refer to the table above for the correct measuring method.
- Mix thoroughly: Shake well to ensure even distribution of the oil.
- Fill engine: Pour the mixture into the tank.
Benefits of Using a 30:1 Fuel Ratio
- Provides excellent engine lubrication.
- Reduces carbon deposits and smoke.
- Maintains optimal engine performance.
- Longer engine life
Note: You can use 2 stroke oil mixing calculator for accurate results.
Common Mistakes to Avoid
- Too much oil → Heavy smoke, dirty spark plugs
- Too little oil → Overheating, rapid wear
- Mixing oil in a dirty container → Fuel contamination
Final Thoughts
Maintaining a 30:1 fuel/oil ratio is easy but essential to prolonging engine life. Always follow the ratio chart, use high-quality oil, and mix carefully. Your two-stroke engine will perform better and last longer.
Here are the other fuel mixing charts, which are 50:1, 40:1, and 60:1.