25:1 fuel mix: how much oil per gallon?
For a 25:1 mix, add 5.1 fl oz (151 ml) of 2-stroke oil to each US gallon of gas, or 40 ml per liter. That is 4 % oil.
A 2.6 fl oz bottle of oil goes with 65 fl oz (1.92 L) of gas at 25:1.
25:1 oil per US gallons of gas
25:1 oil per US gallons of gas| Gas | Oil | In spoons |
|---|
| 1 gal | 5.1 fl oz (151 ml) | 10.2 tbsp · 30.7 tsp |
|---|
| 2 gal | 10.2 fl oz (303 ml) | 20.5 tbsp · 61.4 tsp |
|---|
| 2.5 gal | 12.8 fl oz (379 ml) | 25.6 tbsp · 76.8 tsp |
|---|
| 3 gal | 15.4 fl oz (454 ml) | 30.7 tbsp · 92.2 tsp |
|---|
| 5 gal | 25.6 fl oz (757 ml) | 51.2 tbsp · 153.6 tsp |
|---|
25:1 oil per liters of gas
25:1 oil per liters of gas| Gas | Oil |
|---|
| 1 L | 40 ml (1.4 fl oz) |
|---|
| 4 L | 160 ml (5.4 fl oz) |
|---|
| 5 L | 200 ml (6.8 fl oz) |
|---|
| 10 L | 400 ml (13.5 fl oz) |
|---|
| 20 L | 800 ml (27.1 fl oz) |
|---|
Every common ratio, per gallon and per liter
Every common ratio, per gallon and per liter| Ratio | Oil per gallon | Oil per liter |
|---|
| 50:1 | 2.6 fl oz (76 ml) | 20 ml |
|---|
| 40:1 | 3.2 fl oz (95 ml) | 25 ml |
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| 32:1 | 4 fl oz (118 ml) | 31 ml |
|---|
| 25:1 | 5.1 fl oz (151 ml) | 40 ml |
|---|
| 20:1 | 6.4 fl oz (189 ml) | 50 ml |
|---|
50:1 means 50 parts gas to 1 part oil: oil = gas ÷ 50, gas = oil × 50. 1 US gal = 128 fl oz = 3.785 L; 1 imperial gal = 4.546 L. Spoons are US: 1 tbsp = 1/2 fl oz, 1 tsp = 1/6 fl oz.
Estimates. Follow your engine manual’s ratio and the oil maker’s label. Mix outdoors in an approved fuel can, away from sparks and flames.
Frequently asked questions
How much oil per gallon at 25:1?
For a 25:1 mix, add 5.1 fl oz (151 ml) of 2-stroke oil to each US gallon of gas, or 40 ml per liter. That is 4 % oil.
How much oil for 5 gallons at 25:1?
25.6 fl oz (757 ml): 5 × 128 = 640 fl oz of gas, and 640 ÷ 25 = 25.6.
What percent oil is 25:1?
4 %: 1 part oil to 25 parts gas, and 1 ÷ 25 = 0.04. Use the ratio your engine’s manual gives.