How to Mix Chainsaw Gas? What Proportions of Gas and Oil Should Be Mixed?

You must have heard about how important it is to have an appropriate mix of gas and oil in your chainsaw. 

All types of Chainsaws work best when they’re provided with the perfect quality and quantity of oil and gas. For higher efficiency and greater durability of the chainsaw, it is very important to mix just the required proportion of gas and oil.

How to mix oil and gas for chainsaws? Well, this is what you’re going to read about in this article. Chainsaws are expensive investments and if you’re being careless about the fuel and gas mixture fill-ups, you’re doing a huge mistake. In order for an engine to last a long time and remain healthy, quality gasoline is essential.

Lower octane fuel increases temperatures in the engine and damages internal parts. Never operate your chainsaw with low-quality or cheap fuel.

Let’s study further what steps are to be followed to mix chainsaw gas.

Steps to Follow for Mixing Chainsaw Gas

For mixing chainsaw gas, your chainsaw would probably require a 40-to-1 or 50-to-1 ratio mixture of oil and gas. If you don’t already know about these proportions, you’ll know by reading this article further.

  • Make Sure Your Gas and Oil Are the Right Types
  • Container Selection
  • Identify your mix
  • Fill up with gas and oil
  • Continue to fill with gasoline
  • Prepare your saw for use

Steps to Follow for Mixing Chainsaw Gas

STEP 1: Make Sure Your Gas and Oil Are The Right Types

By the right type of gas and oil, we mean the high-quality gas and oil that is best suitable for your saw, so that, they benefit your chainsaw in the long term as well, rather than just benefitting temporarily. 

Fuels with lower octane ratings can damage the engine’s parts and affect its temperature. So, we recommend using 89 octanes. For the oil, it is a must to use a 2-cycle or 2-stroke oil. Do not use any other type of oil.

STEP 2: Container Selection

For the mixing of chainsaw gas, you’ll need a container. You might think it’s okay to use a milk jug, glass container, or any other such container. But Factory Mutual or Underwriters Laboratory-approved fuel should be the only ones you should use.

STEP 3: Identify your mix

It’s extremely important to identify the mixing proportion. It’s either going to be 40:1 or 50:1 but if you don’t know the proportion, check out the chainsaw manual.

STEP 5: Fill up with gas and oil

To fill up gas and oil, you’re first going to pour gas, about half of it. Now add in all of the oil that is needed to prepare the perfect mixture. When you’re done, close the container and shake it well for a few seconds. 

STEP 6: Continue to fill with gasoline

Now, the remaining half gas that you put aside in step 5, has to be added to the gas container and shaken well for another few seconds.

STEP 7: Prepare your saw for use

Now that you’re done with mixing the gas with fuel, you can now prepare your saw for use. Pour the mixture into the fuel tank until it is approximately 75% full.

How Long Would Mixed Chainsaw Gas Last?

The mixture of chainsaw gas and fuel would typically last about three months. You should never store it more than that because gas can become stale when stored for an extended period of time.

How Long Would Mixed Chainsaw Gas Last

What Are 40 to-1 and 50 to-1 Mixture Ratios?

40 to 1 Mixture Ratio

  • 1 gallon of gasoline to 3.2 fl oz of oil
  • 2 gallons of gasoline to 6.4 fl oz of oil
  • 3 gallons of gasoline to 9.6 fl oz of oil
  • 4 gallons of gasoline to 12.8 fl oz of oil
  • 5 gallons of gasoline to 16 fl oz of oil

50 to 1 Mixture Ratio

  • 1 gallon of gasoline to 2.6 fl oz of oil
  • 2 gallons of gasoline to 5.12 fl oz of oil
  • 3 gallons of gasoline to 7.69 fl oz of oil
  • 4 gallons of gasoline to 10.24 fl oz of oil
  • 5 gallons of gasoline to 12.9 fl oz of oil

Benefits of Pre-Mixed Fuel

There are some great benefits of premixed fuels. 

Performance that meets expectations

It can enhance, lubricate, and maximize the performance of your two-stroke engine when you use quality fuel and additives.

An easy way to save time

Pre-mixed fuel saves time without a doubt. Oil and gasoline don’t have to be mixed precisely. Ordering it online is possible.

Benefits of Pre-Mixed Fuel

A long-term investment

Open containers last two years and sealed containers last three years. So, having a pre-mixed fuel is a long-term investment.


How to Mix Chainsaw Gas – FAQs

How to mix gas for Stihl chainsaw?
Mixing gas is the same for all the chainsaws, may it be Stihl or any other. And the steps to be followed are the ones described above in our article.
What is the best fuel for a chainsaw?
It is recommended to use unleaded gasoline that has an octane rating of 89 or higher. It has been found that engines with a lower octane can have some issues. The engine temperature can be increased, piston seizures may occur, and the engine can be damaged too.
What is 2-stroke oil ratio?
Mix the oil in the two-cycle engine at a 40:1 ratio. This makes a mixture of one gallon of gasoline and three ounces of two-cycle engine oil.
How do you mix 50 to 1 chainsaw fuel?
It means that 50 parts of gas should be mixed with one part of two-stroke oil if your manufacturer recommends a 50:1 fuel/oil mix. Two-stroke oil should be added to one gallon of gas to make the 50:1 mixture
What is STIHL mix ratio?
Stihl’s gasoline-powered chainsaws use 50:1 of gas and oil mixture.


You might want to read about Best Stihl Chainsaw Reviews.


A perfect proportion of gas and oil is necessary for the efficient working of the chainsaw and a good lifespan. So, make sure you provide your chainsaw with the appropriate ratio.

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