How Do You Mix Gas for a Chainsaw?

On this page (8 sections)

1. How do you mix gas for a chainsaw safely?
2. What ratio should you use when mixing gas for a chainsaw?
3. Which oil should you choose for mixing chainsaw gas?
4. Is premixed fuel easier than mixing your own?
5. What common mistakes should you avoid when mixing chainsaw gas?
6. How should you store mixed chainsaw fuel?
7. What should you check before starting the chainsaw?
8. Which chainsaw fuel option should you choose?

If you're learning how to mix gas for a chainsaw, use the fuel-to-oil ratio in that saw's manual. Measure the required gasoline and two-stroke oil into an approved fuel can, blend them, and label the container before filling.

The ratio, gasoline type, and oil requirements can vary by engine. Check the manual and fuel cap first; a bottle marked 50:1 is useful only when your saw calls for that mix.

How do you mix gas for a chainsaw safely?

Measure fresh fuel and the correct two-stroke oil outdoors, using a clean, approved fuel container. Keep the work area away from flames, sparks, and smoking, and avoid spills on your skin or clothes.

1. Read the manual for the required gasoline type, octane, and fuel-to-oil ratio.
2. Pour the measured gasoline into the fuel container.
3. Measure the oil for that amount of gasoline.
4. Add the oil, close the container, and gently shake to blend.
5. Label the can with the ratio and date, then fill the saw as directed.

Make a batch sized for the work you expect to do, rather than keeping a large amount around. Wipe up any spilled fuel and move the saw away from the fueling spot before starting it.

A dedicated fuel can and a measuring cup marked in fluid ounces make small batches easier to measure. Use equipment intended for fuel, keep its cap closed between steps, and don't use a food container that could be mistaken for something else.

What ratio should you use when mixing gas for a chainsaw?

Use the ratio specified by the saw's maker. A 50:1 mix means 50 parts gasoline to 1 part oil by volume, but it isn't a universal setting for every chainsaw.

At 50:1, the common US measure is 2.6 fluid ounces of oil per 1 US gallon of gasoline. For a half gallon, use 1.3 fluid ounces; for 2 gallons, use 5.2 fluid ounces.

These measures apply only when the manual calls for 50:1. If it specifies a different ratio, use that ratio and calculate the oil amount for your chosen fuel volume.

How do you calculate oil for a 50:1 chainsaw mix?

For a 50:1 mix, divide the gasoline volume by 50 to find the oil volume in the same units. In practice, use a ratio chart or a marked measuring container so you don't have to calculate while handling fuel.

Keep the oil and gasoline amounts tied to the same batch. Don't assume that one small bottle will cover every container size, or pour in an extra amount to compensate for uncertainty.

Which oil should you choose for mixing chainsaw gas?

Choose two-stroke oil suited to outdoor power equipment, then follow the oil and ratio requirements in your saw's manual. The products below suit different buying preferences, but none changes the ratio your engine requires.

Echo Power Blend Gold is a semi-synthetic 50:1 oil for two-stroke outdoor power equipment, including chainsaws. Its 2.6 fl oz bottles are sized for a gallon of gasoline at 50:1, and the six-pack suits someone who regularly mixes batches or also fuels other compatible equipment.

Echo says the blend includes a fuel stabilizer and detergent and is designed for lower smoke emissions and protection against rust. Skip it if you need a different ratio or your saw manual requires another oil specification.

Stihl HP Ultra is a synthetic 50:1 two-cycle oil in a three-pack, with each 2.6 oz bottle intended for a gallon of fuel. Choose it if you want Stihl-branded oil in measured bottles and your manual permits a 50:1 mix.

Skip it if your saw calls for another ratio.

Husqvarna XP+ comes in 2.6 oz bottles, sold in a six-pack. It's a practical choice for a Husqvarna owner who wants the brand's two-stroke oil in measured amounts; check your manual's ratio before using a full bottle, since the bottle size alone doesn't guarantee the correct mix.

Is premixed fuel easier than mixing your own?

Premixed fuel removes the measuring step, but its ratio and fuel type still have to match your saw. Check the container and your manual before pouring.

Stihl MotoMix is ready-mixed at 50:1 for two-cycle engines that require that ratio. The 1 quart can suits occasional users who want a small supply without buying gasoline and measuring oil; it is also a fit when you want premixed fuel without ethanol.

Skip it if your saw requires another ratio or fuel type.

Don't add oil to premixed fuel or combine it with another batch. Either step changes the prepared mixture, so use it as directed on its container and in the saw manual.

What common mistakes should you avoid when mixing chainsaw gas?

The main mistakes are guessing the ratio, using the wrong oil, and fueling carelessly. A wrong mix can cause poor running or engine damage, while gasoline vapors can ignite around a flame or spark.

• Don't copy another saw's ratio. Check your own manual and fuel cap.
• Don't use straight gasoline in a two-stroke saw that requires premix.
• Don't estimate oil by eye. Small measuring errors matter more in a small batch.
• Don't add extra oil to make the mix seem safer. Use the specified ratio.
• Don't use a dirty or unapproved container. Residue or the wrong container can make handling less safe.
• Don't fuel beside an ignition source or start the saw where you mixed fuel. Clean up spills and move to a clear area first.

If you're still choosing a saw, our plain guide to gas chainsaws explains what to consider for home use. For protective equipment, see our chainsaw safety gear guide.

How should you store mixed chainsaw fuel?

Keep mixed fuel in a sealed, approved container marked with its ratio and mix date. Store it in a cool, dry place away from children, heat, and ignition sources, and follow the fuel container and saw manual instructions.

Make only as much as you expect to use soon. Storage time depends on the fuel, oil, container, and conditions, so don't assume every mix stays fresh for the same length of time.

If you won't use the saw for a while, prepare it according to its manual. Our guide to storing a chainsaw between jobs covers the steps to take during a break.

What should you check before starting the chainsaw?

Secure the fuel cap, check for leaks, and move the saw away from the fueling area before starting. Follow the maker's starting procedure and wear the protective gear named in the manual.

If fuel leaks or the saw runs poorly after refueling, stop and check the manual before using it again. Don't try to fix a running problem by adding oil or gasoline without checking the mixture first.

Which chainsaw fuel option should you choose?

Choose measured two-stroke oil when you want to make fresh batches, or compatible premix when you want to skip measuring. For either option, the manual decides the ratio and fuel requirements.

Echo Power Blend Gold and Stihl HP Ultra suit users who need 50:1 oil in measured bottles; Husqvarna XP+ suits owners who prefer that brand's oil, with the ratio confirmed before measuring. Stihl MotoMix suits a 50:1 saw owner who wants ready-to-use fuel in a quart can.

The safest routine is simple: confirm the manual's requirements, measure accurately, label the can, and store it as directed. For more help choosing a saw for your needs, see our guide to the best gas chainsaws for home use.

Frequently asked questions

What gas to oil ratio does a chainsaw use?

Use the ratio stated in your chainsaw's manual or on its fuel cap. Many two-stroke saws use 50:1, but the required mix depends on the engine, and the wrong ratio can cause damage.

At 50:1, mix 2.6 fluid ounces of oil with 1 US gallon of gasoline.

Can I use regular gas in a chainsaw?

Use gasoline that meets your saw maker's requirements for octane and fuel type, mixed with the correct two-stroke oil if the saw requires premix. Don't put straight gasoline in a two-stroke engine or assume that fuel suitable for a car is suitable for your saw.

Can I use premixed fuel in my chainsaw?

Yes, if the premixed fuel's ratio and fuel type match your chainsaw's manual. Check the container before pouring, since premix is intended for engines with a specific mix requirement.

A compatible premix can save you from measuring and blending gasoline and oil yourself.

How long can chainsaw gas sit?

Storage time depends on the fuel, oil, container, and the saw maker's guidance. Mix only what you expect to use soon, mark the container with the mix date, and follow the manual's storage instructions.

For longer breaks, prepare the saw for storage as its maker directs.