Small engines are used in a variety of applications, including lawnmowers, chainsaws, weed trimmers, and generators. These engines are typically two-stroke, which means that they mix gasoline and oil together to create fuel. The ratio of gasoline to oil is important for proper engine lubrication and performance.


What is a Small Engine Oil Ratio?

A small engine oil ratio is a number that represents the amount of oil that is mixed with a given amount of gasoline. For example, a 50:1 oil ratio means that there is one part oil to 50 parts gasoline. The lower the ratio number, the more oil is used per gallon of gasoline.

Why is Oil Ratio Important?

The oil in a small engine lubricates the moving parts of the engine, such as the pistons, cylinders, and bearings. The oil also helps to cool the engine and prevent carbon buildup. If the oil ratio is too low, the engine will not be properly lubricated and may suffer premature wear. If the oil ratio is too high, the engine will not run as efficiently and may produce more emissions.

Common Oil Ratios

The most common oil ratios for small engines are 50:1, 40:1, and 32:1. These ratios are recommended by most engine manufacturers. However, some engines may require a different oil ratio. It is important to consult the owner’s manual for the specific engine to determine the recommended oil ratio.

How to Mix Oil and Gasoline

To mix oil and gasoline, you will need a clean gas can and a funnel. First, add the recommended amount of oil to the gas can. Then, add the gasoline. Be sure to mix the oil and gasoline thoroughly before using it in the engine.

How to Store Oil and Gasoline

Oil and gasoline should be stored separately in a cool, dry place. Do not store oil and gasoline in the same container.


If you are having problems with your small engine, one of the first things to check is the oil ratio. If the oil ratio is too low, the engine may not start or may run poorly. If the oil ratio is too high, the engine may smoke or may not run as efficiently.


The oil ratio is an important part of small engine maintenance. By following the recommended oil ratio, you can help to ensure that your engine runs smoothly and lasts for many years.

Additional Tips

  • Use only high-quality oil and gasoline.
  • Change the oil and filter regularly.
  • Clean the air filter regularly.
  • Store the engine in a cool, dry place.

By following these tips, you can help to keep your small engine running smoothly and efficiently for many years to come.