2-Cycle Oil Mix Calculator & Chart

Outboard engines, leaf blowers, weed trimmers and other equipment with small engines often have a 2-cycle, also known as 2-stroke, engine. If the engine has a single fill port for both engine oil and gas, it is a 2-cycle engine that requires a specific mix of oil and gas to function properly.

What Is the Right Ratio

The mixture of gas and oil is written as a ratio that represents the parts of gasoline and the parts of oil. The ratio needed in the 2-cycle oil mix for your engine can be found in the equipment operator’s manual or on the engine label. If you cannot locate either, but know the equipment’s age, refer to the following: most handheld equipment manufactured before 2003 requires a 32:1 ratio; most handheld equipment made after 2002 uses a 40:1 or 50:1 ratio. Most outboard motors require a 50:1 ratio.

How to Create the Oil Mix

  1. Pour the correct amount of 2-stroke oil into a clean gas can.
  2. Add the correct amount of gasoline.
  3. Stir or shake the container to mix the oil and gas.
  4. Use the mixture within 30 days or add fuel stabilizer to extend the shelf life.

2-Stroke Oil Mix Calculator

  • For a 50:1 ratio of gas to oil, use 2.6 fluid ounces of oil per gallon of gas.
  • For a 40:1 mixture, use 3.2 fluid ounces of oil per gallon of gas.
  • For a 32:1 mixture, use 4 fluid ounces of oil per gallon of gas.

Important Warnings

  • Do not use automobile motor oil, which contains noncombustible additives that will damage your engine; only use 2-cycle engine oil.
  • Do not use gasoline with more than 10 percent ethanol, which attracts moisture, causes gasoline to break down and can lead to engine damage.
  • Do not guess at the right ratio or approximate the amounts of either gasoline or oil; your engine requires a specific mixture of fuel and lubrication to run properly.
  • Do not combine the gas and oil in the engine directly; always mix in a separate, clean container.
  • If your engine has been idle for more than a month, such as when coming out of winter storage, check the fuel to make sure the mixture hasn’t degraded.

The mixture of gas and oil is written as a ratio that represents the parts of gasoline and the parts of oil.

The contents of this blog are for informational purposes only and are not intended for diagnosing. Gold Eagle Company does not guarantee - expressed or implied - any specific results and a professional should be consulted on more serious issues.

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  • There are some gas stations that sell ethanol free gas. Check out google or equivalent in your area to find them. This gas is much better but you may also need to add a little octane booster since many only sell 87 octane ethanol free gas.