Here are Chainsaws Using a Mixture of Gas and Oil

You can’t expect your chainsaw to function properly and safely if you use just any kind of fuel in it. To keep your chainsaw in top shape, you need to pay special attention to the fuel you put in it.

Understanding which gas to put in a chainsaw when confronted with the wide variety of fuels available at gas stations today can be a daunting task. Most modern chainsaws use a 2-cycle engine, which calls for a blend of gas and high-quality 2-cycle engine oil.

Fuel should be stored in a cool, dry place away from direct sunlight and moisture, used within 30 days, and discarded otherwise. Keep working in an open space with plenty of airflow.

Chainsaw Gas
Chainsaw Gas

Prior to diagnosing, repairing, or operating the equipment, make sure you’ve read and understood all of the safety instructions that came with it. If you are unsure of how to proceed, lack the necessary expertise, or are unable to do so safely, you should seek the assistance of a professional.

Never Use Old Gas in a Chainsaw.

Fuel management is one of the most important aspects of chainsaw operation. If fuel from a chainsaw has been sitting for a while, it may attract moisture and leave behind varnish and gummy deposits.

This can lead to a clogged fuel system and eventual part failure, which in turn could prevent the vehicle from starting or running smoothly. The engine’s performance may suffer if you use stale fuel. The chainsaw might not seem as powerful as it should be.

In a short amount of time, gas loses its integrity. For this reason, gas should be used up no later than 30 days after purchase. If you want your gas to last a little longer, you can stabilize it with a fuel additive like Sea Foam Motor Treatment.

The stabilizing agent is already built into some oils. Don’t assume the fuel is good for a long time because a stabilizer is included. Oils with added fuel stabilizers can extend the life of fuel by anywhere from 30 days to 2 years.

Unleaded gasoline with a mid-grade octane rating of 89 or higher and no more than 10% ethanol is recommended for chainsaws (E10). You should never put E15, E30, or E85 in the engine because doing so will cause severe damage and will likely void any warranties you may have purchased.

A chainsaw with a 2-cycle engine requires the use of high-quality 2-cycle engine oil.

After 30–90 days of purchase, many companies refuse to replace chainsaw carburetors under warranty due to the damaging effects of fuel. Misusing your chainsaw due to improper fuel or fuel quality is not the responsibility of the manufacturer.

The best fuel for your string trimmer is one without ethanol, but it will cost you more.

Ethanol-Free Fuels for Chainsaws

  • 2-Cycle 50:1 Premix
  • 2-Cycle 40:1 Premix
  • 4-Cycle Fuel

The Proper Fuel and Oil for a Two-Cycle Chainsaw

Mixture of 2-Cycle Gas and Oil for a Chainsaw

Do not risk damaging a chainsaw by accidentally filling it with the wrong fuel. A two-cycle chainsaw’s engine will seize and be damaged beyond repair if straight gasoline is poured into it.

When gasoline is not blended with oil, friction between engine components increases, reducing efficiency.

The ratio of gas to oil in a chainsaw’s 2-cycle engine is either 50:1 or 40:1. The correct mixture can be found in the operator’s manual or on the original fuel cap.

Create this fuel blend using unleaded gasoline that has an octane rating of 89 or higher (mid-grade) and no more than 10% ethanol. It’s recommended to use an ISO-L-EGD and JASO M345 FD certified 2-cycle premium engine oil. DO NOT use regular motor oil.

Here are some common chainsaw brands and the current fuel-to-oil mix ratios they need:

ManufactureGas to Oil Mix2-Cycle OilPremixed Fuel
ECHO50:1EchoRed Armor Pre-Mix
Husqvarna50:1HusqvarnaXP Pre-Mix
Poulan Pro50:1Poulan Pro
Stihl50:1StihlMoto Mix Pre-Mix

How to properly mix gas and oil for a 2-cycle chainsaw:

  • Use the following chart to figure out how much fuel mix to make.
  • Empty the gas from a legal container. In a gas can, pour in unleaded fuel with an octane rating of at least 89 and no more than 10% ethanol.
  • Refer to the oil quantity needed per gallon of fuel in the can. Two-cycle oil should be added to the gas.
  • Change the cap.
  • The fuel and oil should be gently shaken together to combine them.
  • Put some more gas in the chainsaw’s tank.

2-cycle oil is acceptable. This Kawasaki two-cycle hybrid is another option. The 50:1 mixture requires 2 gallons of gas and comes in 5.2 oz. and 6.4 oz. bottles. Two gallons of gas and one 6.4-ounce bottle of oil equals a 40:1 ratio.

2-Cycle Gas to Oil Mix Ratio

Gas to Oil Mix1 Gallon2 Gallon2.5 Gallon
50:12.6 oz5.2 oz6.4 oz
40:13.2 oz6.4 oz8.0 oz
32:14.0 oz8.0 oz10.0 oz

2-Cycle Premixed Fuel

Premixed fuel is a great alternative to using ethanol due to its harmful effects. Premixed fuel is readily available from many manufacturers, and it does not contain ethanol.

This is a useful thing to keep on hand so that you won’t have to rush out to the gas station and deal with fuel mixing when you really need to.

Utilizing an ethanol-free fuel blend is a great way to lessen fuel-related issues and increase engine longevity. Premixed fuels are widely available from a variety of manufacturers.

This TruFuel 40:1 or 50:1 premixed fuel can be used instead. This oil and fuel mixture is suitable for use in your chainsaw’s fuel tank and contains no ethanol.

Oil and Gasoline for a Four-Cycle Chainsaw

Gas For The Engine Of a Four-Cycle Chainsaw

While most chainsaws on the market today are powered by 2-cycle engines, some newer models are being produced with 4-cycle motors.

Direct gasoline is needed for 4-cycle engines. Fuel and oil can be refilled through their own dedicated filler ports on a 4-cycle engine. If you’re trying to figure out what kind of chainsaw engine you have by counting the number of fill ports, you might get confused between these and the port for adding oil to the bar and chain.

Don’t put any ethanol in your gas tank if the percentage is higher than 10% and use gas with an octane rating of 89 or higher. Fuels with higher ethanol contents should be avoided. Chainsaws perform best when fed fuel with low ethanol levels or fuel with no ethanol at all.

Oil For The Engine Of a Four-Cycle Chainsaw

Both the engine oil and the fuel are refilled through different ports on 4-cycle engines. When operating a 4-cycle motor, NEVER combine the oil and fuel. Two-cycle oil is not suitable for a four-cycle chainsaw.

The engine’s moving parts can’t function without oil. Overheating caused by excessive friction prevents a chainsaw from starting, and using the wrong kind of oil can ruin the engine.

You may need to switch to a different viscosity of engine oil if you plan on using your chainsaw in extreme heat or cold.