2-Stroke Fuel Mixture Calculator
Ensure the longevity and performance of your 2-stroke engine by using the perfect fuel-to-oil ratio. Enter your details below to get the precise amount of oil to add to your gasoline.
Gallons (US)
Liters
:
1
How to Use the 2-Stroke Mix Calculator
Getting the correct mixture is simple with our tool:
- Enter Gasoline Amount: Input the quantity of gasoline you will be using.
- Select Units: Choose whether the gasoline amount is in US Gallons or Liters.
- Enter Mix Ratio: Input the ratio recommended by your equipment's manufacturer (e.g., for a 50:1 ratio, enter "50"). You can usually find this information in the user manual or printed on the device itself.
- Calculate: Click the "Calculate Oil Amount" button to see the exact amount of 2-stroke oil you need to add.
Understanding 2-Stroke Fuel Ratios
A 2-stroke fuel ratio, like 40:1 or 50:1, specifies how many parts of gasoline should be mixed with one part of oil. For example, a 50:1 ratio means you need to mix 50 parts of gasoline with 1 part of oil.
Here is a quick reference table for common ratios:
| Ratio | Oil Percentage | Oil per Gallon of Gas (US oz) | Oil per Liter of Gas (ml) |
|---|---|---|---|
| 25:1 | 4.0% | 5.12 oz | 40 ml |
| 32:1 | 3.1% | 4.0 oz | 31.25 ml |
| 40:1 | 2.5% | 3.2 oz | 25 ml |
| 50:1 | 2.0% | 2.56 oz | 20 ml |
Why is the Correct Fuel-to-Oil Ratio Important?
Unlike 4-stroke engines, 2-stroke engines do not have a separate lubrication system. The oil mixed with the gasoline is responsible for lubricating critical engine components like the piston, cylinder, and crankshaft bearings. An incorrect ratio can lead to serious problems:
- Too Little Oil: This is the most dangerous mistake. Insufficient lubrication causes increased friction and heat, leading to rapid wear, piston scoring, and ultimately, catastrophic engine seizure.
- Too Much Oil: While less damaging than too little oil, an overly rich oil mixture can cause fouled spark plugs, excessive smoke, carbon buildup on the piston and exhaust port, and reduced engine performance.
Always follow the manufacturer's recommendation to ensure your engine runs smoothly and lasts for years.
Manual Calculation Example
Let's say you need to mix 2 gallons of gasoline for a chainsaw that requires a 40:1 ratio.
- Convert Gasoline to a smaller unit: Since there are 128 fluid ounces in a US gallon, you have 2 gallons * 128 oz/gallon = 256 oz of gasoline.
- Calculate the Oil Amount: Divide the total gasoline ounces by the ratio number. 256 oz / 40 = 6.4 oz.
You would need to add 6.4 fluid ounces of 2-stroke oil to your 2 gallons of gasoline.
Tips for Mixing 2-Stroke Fuel
- Always use a clean, dedicated, and approved fuel container.
- For the best mix, pour in about half of the gasoline first, then add the measured amount of oil.
- Seal the container and shake it vigorously for 15-20 seconds to ensure the oil is fully dispersed.
- Add the remaining gasoline and shake again.
- Only mix enough fuel that you plan to use within a month or two, as the fuel-oil mixture can degrade over time.
- Always use high-quality 2-stroke oil designed for your type of equipment (e.g., air-cooled vs. water-cooled).
Error
Please enter valid, positive numbers for gasoline amount and mix ratio.'; return; } var oilInMl; var oilInOz; // Conversion constants var GALLON_TO_ML = 3785.41; var LITER_TO_ML = 1000; var ML_TO_OZ = 0.033814; var gasInMl; if (gasUnit === 'gallons') { gasInMl = gasAmount * GALLON_TO_ML; } else { // liters gasInMl = gasAmount * LITER_TO_ML; } oilInMl = gasInMl / mixRatio; oilInOz = oilInMl * ML_TO_OZ; resultDiv.style.display = 'block'; resultDiv.style.backgroundColor = '#eaf6ff'; resultDiv.style.borderColor = '#b3d9f5'; var resultHTML = 'Oil to Add
'; resultHTML += '' + oilInOz.toFixed(2) + ' oz
';
resultHTML += 'or';
resultHTML += '' + oilInMl.toFixed(2) + ' ml
';
resultHTML += 'For ' + gasAmount + ' ' + gasUnit + ' of gas at a ' + mixRatio + ':1 ratio.';
resultDiv.innerHTML = resultHTML;
}