Chain Saw Gas Oil Mix Ratio – Is 50:1 For All?

The chainsaw is one of the most used cutting tools in woodworking. So when you use it, you should know how much gas and oil should be mixed together. There are few mixing ratios that you can minimize fuel consumption and increase performance well. So let’s see in detail about chainsaw gas mix ratios with the correct proportion.

Most chainsaws need a 50:1 fuel/oil mix ratio (2.6oz oil per gallon) for the 2-stroke engines. Some chainsaws require a 40:1 fuel/gas ratio (3.2oz oil per gallon). In order to reduce the inside friction and heat, older chain saws use a 30:1 fuel oil ratio.

The gas mixing ratio depends on the type of chainsaw and cc. When you mix oil with gas, you should have fresh fuel (gas) which is not older than 06 weeks. So let’s see, how to mix the oil with fuel in chainsaws properly with its effect. So let’s keep reading on.

12 Types Drill Bit for Wood
12 Types Drill Bit for Wood

Chainsaw Gas Mix Ratio

What Is 50 To 1 Gas Mix Ratio?

When your chainsaw’s manufacturer recommends a 50:1, fuel-to-oil mix ratio, you need 50 parts of gasoline need to mix with one part of oil.

If you mix one liter of fuel at a 50:1 ratio, you have to add 20 milliliters of oil. It is easy to calculate the 50:1 fuel-to-oil ratio.

When you move to other gas mix ratios such as 40:1, 32:1 and 25:1, the below conversations will help.

  • 1 gallon = 128 ounces, So 1 gallon needs 2.6 ounces of oil
  • 1 liter = 1000 milliliters, So 1 liter needs 20 milliliters of oil
Gas to oil 50:1
Gas to oil 50:1

Chainsaw Gas Mix Ratio Table

Chainsaw engines are 2-stroke engines. So we should use additional lubricants with fuel in order to control heat and friction inside. So mostly, the gas mix ratio for the chainsaws is 50:1. You can follow the below table when you mix oil with gas.

Fuel Amount
(Gallon or Ltr)*
Oil amount in
mixture Ounces (oz)
Oil amount in
mixture milliliters (ml)
12.620
25.240
37.860
410.480
513100
615.6120
719.2140
821.8160
924.4180
1026200
Chainsaw gas mix ratio 50:1

When you mix, you should use a standard unit such as Gallon – Ounces or Liter – Milliliters

Why Do Chainsaws Need a Gas Mixture?

When you use a 2-stroke chainsaw, an oil mixture is very important for its protection due to heat and inside friction.

If you use only gasoline in a 2-stroke engine, it will cause to increase the heat. When you mix oil with fuel, it will cool the piston and cylinder to keep them eventually lubricated.

A proper gas: oil mixture helps for moving engine parts smoothly and reduces the machine heat, and protects the piston and crankcase from getting damaged. And also, using only gasoline cause to chainsaw’s low performance, and sometimes your chainsaw lifetime will reduce. So you had better use a proper gas mixture on your chain saw every time.

Which Oil Need To Mix With Chainsaw Fuel?

Chainsaw fuels
Chainsaw fuels

When we mix oil with fuel, we can see, many types of oil in the market. So let’s see, how to choose the suitable oil which is highly compatible with the chainsaw engine.

  • Simple mineral oil – Derives from fossil oils
  • Synthetic oil – Mix mineral oils and additives such as detergent and stabilizers to burn better
  • When you use gasoline, it should have a minimum of 89% of octane and no more than 10% ethanol content. If your octane rating is below 89% may increase the engine temperatures.
  • When the ethanol content is more than 10% will cause running problems and major damage in the engine.
  • If you use various ethanol content fuels, you should adjust the carburetor because it affects the engine speed.
  • Shake well after you mix oil with fuel

Synthetic oil is really good for chainsaws. Because it produces lower deposits and emissions due to lower ash content, sometimes, mineral oils can contain non-lubricants and solvents and additives that allow easier gasoline mixture. But it causes a higher amount of emissions, and sometimes those can harm the environment. These best 2-stroke oils will run your engine smoothly.

STIHL Chainsaw Fuel Mix Ratio

For STIHL chainsaws, all models generally use a 50:1 mixing ratio. In some special cases this will be varied. So I strongly suggest you check the manufacturer’s manual before you use it.

  • 1-liter gasoline mix with 20 milliliters STIHL oil,
  • 5l with 100 ml
  • 10 l with 200ml.

Can You Use Only Gasoline In Chain Saw? 

Do not use only gasoline in chainsaws
Do not use only gasoline in chainsaws

You can’t use only gasoline in chainsaws because the chainsaw engine is a 2-cycle engine. We called this is a 2-stroke engine. When only gasoline is combusting inside lot of heat is generated. And there will be high friction. Due to this, engine heat will go up and inside parts, rubbers, bushes, and rings can be melted easily due to heat.

So do not let destroy the engine without using only gasoline. By accident, if you fill the chainsaw in a gas station, don’t forget to mix the oil (2T).

I found a guide for Oil And Gas mixing for outdoor tools.

Can you Fill Chainsaw Directly from Gas Stations?

Gasoline comes with ethanol. Ethanol is an alcohol, and it attracts water, so it pulls water into your fuel system, which is bad for your chainsaw’s engine.

Secondly, olefin chemicals can find in your regular station gas. That chemical produces a gummy kind of residue and varnish kind of stuff in your carburetor and damages your carburetor.

With my experience, I would like to recommend you to use ethanol and olefin-free gasoline, which is good for your chainsaw’s life.

What Happens If I Mix Too Much 2-Stroke Oil?

Proper Gas-to-Oil mixture color
Proper Gas-to-Oil mixture color

When you add too much oil to the fuel mixture for chainsaws, You can see smoky exhaust leaking out of the muffler and sometimes loss of power. So those problems can fix easily by replacing fuel in the tank.So always mix the fuel and oil according to the recommended ratio.

Additionally, when you add too much 2-stroke oil in your chainsaw, carbon, and oil will be deposited. So it clogs the whole system, and air can’t move in-out. So the engine will overheat rapidly.

And also, because of too much oil you will get a huge carbon build-up right on the piston and exhaust port, and it’s eventually going to break off, and it’s going to get stuck between the piston and cylinder, it is causing to piston and cylinder’s long run score up. So most suitable for using a manufacturer guide and use a suitable mixing ratio like 50:1, 40:1, or 32:1 as your manufacturer guide.

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Tom Mackenzy

I am Tom, I am really interested in DIY projects. I have my own workshop and I spend my free time with so many projects. So I would like to share my experience with you regarding power tools, woodworking, metalworking, etc.

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