Although modern gas powered chainsaws are very efficient and advanced these days, there is one thing they all still want you to do. Mix your oil and gas in the same fuel tank!

mixing oil and gas for chainsaw

Not mixing oil and gas together may cause a lot of head-scratching when you pull the starter cord, and you get a few false starts, but your chainsaw will not start running. You might of forgot to mix in oil all together or maybe you just  mixed the gas and oil wrong ratio for the chainsaw you own. Today are going to show you how to do it right.

To do this right, you are going to need a few things up front before you start.

A chainsaw and its operator manual, the correct gas, the recommended oil, an approved container, and along with this a set of tables that tell you how much of oil goes with how much gas. The ratio of oil to gas is critical for not only for the longevity of your chainsaw but getting it running right in the first place.

The first thing you need to do is get out your owner’s manual and find the section on mixing the gas and oil.

When reading your manual you will need to look out for the wording and measuring units, as sometimes companies are often selling international products, with non-US manuals. The three main things to remember are:

  1. You may note the word “Petrol.” You laugh at this, as you know it is another word for gas. However, sometimes this can get confusing if you forget. Therefore, when you look in the manual, you will find something like “chainsaw petrol oil mix.” Again, this seems self-explanatory.
  2. Remember the American system of weights and measures do not go along with the rest of the world. That is why you need to read the manual properly and with an eye for metric units instead of imperial. You need to convert correctly, or you could be setting yourself up for failure with your chainsaw. That is why we will be letting you see some examples of a chainsaw fuel mix chart.
  3. Ratios – For example one manual may state, to mix oil and gas for chainsaw: Use a 50:1 ratio. While another may say mix gas and oil for chainsaw: Use a 50:1 ratio.

50:1 this means only one thing, Gas to Oil. 50 parts Gas to 1 part Oil, just think, should I be filling this saw up with more oil or more gas? The answer of course is more gas! A chainsaw fuel mix chart should follow this golden rule.

Chainsaw Fuel Mix Charts

There are many tables for mixing gas and oil for gasoline-powered machinery out there. The most common mix ratios for chainsaws are 50:1 and 40:1. REMEMBER every chainsaw is different though, check your manual to see what is required for your saw. Below we give you both charts in American (imperial) and Metric Units for a reference:

mixing oil and gas for chainsaw chart US Gallons

mixing oil and gas for chainsaw chart litres and millilitres

mixing oil and gas for chainsaw chart Imperial Gallon

Hopefully the charts above will help you know how to mix oil and gas for your chainsaw.


  • Gal – refers to gallon
  • Imp – short for Imperial measuring system

2 Stroke Mix for Chainsaw

We now have the starting information now to create the two-stroke elixir that will start, run, and protect your chainsaw from wear and tear.

The recipe is quite simple. We need to get the proper gasoline. For a chainsaw, this means unleaded gas with an octane of 89 or better. You also need to make sure that it does not have ethanol mixed in as well.

STIHL sources say you can use up to 10% ethanol. They also say you should be using their proprietary 2-Stoke oil with built-in stabilizers. But, do you know what the real ethanol content is in the gasoline; you get from your supplier. Too much and you end up with a burned out hulk that wouldn’t cut a popsicle stick. So, that is why this writer is a purist when it comes to gasoline.

Next, check your manual and get the recommended oil that it says should be using. You are going to be mixing the gas and oil inside of an approved container.

At this point, you need to do a bit of math. Check the capacity of your chainsaw’s fuel tank. You can find this in your owner’s manual.

Now, you need to figure the amount of fuel you are going to use for the work you are planning. Mixed fuel loses its potency over time. So, you want to be using it while it is fresh. The various chainsaw makers say you can keep the fuel mixture for 30 days to 3 months depending on whom you ask. However, we believe you should not be storing chainsaw fuel as it could pose a health hazard as well as lose its freshness. However, if the fuel is a premixed fuel in a sealed unopened container, you can store it for months or years. (more on that later)

So, let’s start mixing.

  1. Clean the cap and threads of the target container
  2. Using your mixing chart to figure the correct amount of gas and oil you need
  3. Pour the oil in first.
  4. Pour the needed amount of gasoline/petrol in next.
  5. Cap all the containers.
  6. Shake the fuel mixture rapidly to mix thoroughly.

You are now ready to gas up your chainsaw.

Let’s now look at some other things you will want to be aware of as it offers you the whys and an alternative solution to mixing fuel and oil so you wouldn’t have to do go through all of this in the first place.

fueling a chainsaw with mixed gas and oil

Do Chainsaws Use Mixed Gas

Yes, because the 2-stroke engine does not have a dedicated lube system that has a sump and a recalculating pump for the single piston that you find in a two-stroke engine.

So, to prolong engine life and keep everything moving smoothly we mix the fuel and oil together up front. It simplifies the engine design, and that is the way we have been doing it for a long time now.

Premixed Chainsaw Gas

If going through this ritual every few days is not to your liking. You may be using your chainsaw continually, or you are someone who uses it occasionally there is an alternative.

Premixed chainsaw fuel is available for chainsaws. STIHL touts its line of fuel products.–lubricants-and-fuels/

premixed chainsaw fuel

They come in a variety of sizes, and that makes it easier on you as you buy only the amount of fuel you need for a given job. For a contractor or professional, it also makes it for and easy way to do inventory control as you can tell at a glance how many units (containers) you have in your storage sheds. Another advantage is portability, no messy mixing process, and finally no wasted leftover fuel that can go bad.

Amazon has various brands available that match up nicely with the chainsaws out there. Husqvarna offers us their 95/93 Octane premixed fuel. Husqvarna like STIHL adds ingredients to stabilize the fuel and Husky tell us theirs will store for years. So, for a small business, that uses chainsaws, this is an excellent idea.

One of the neat things about using the STIHL fuel when you buy your chainsaw your limited warranty doubles. The writer mentioned earlier that STIHL’s website states you can use up to 10% ethanol in your gas. However, they increase your warranty if you use a fuel that in its blurb tells you that it is “Non-ethanol.” Does that mean they know something we don’t?

But, it is the same for other brands as well that service the needs of other brands of chainsaws that don’t have their brand of premixed fuels.

TruFuel for example, has a 50:1 mix that goes with most other brands of chainsaws. You also get it in six container lots, which if you have multiple chainsaws in use at the same time you can drop off one case per location and your workers have all the fuel they need for a day or so.

Groundskeepers and Lawn care services do this as a case of fuel fits comfortably inside their mobile vans. Also, for businesses like this, it saves them valuable time as a customer pays only for work done and every moment wasted mixing is money lost.

There is just one drawback, the cost. At $7-$8 dollars per quart, you need to look at your ROI of the work you are doing versus the amount going out on labor, fuel, and equipment replacement costs. Repairs also need factoring in; chainsaws do breakdown. So, you need to be cognizant of all of this before using premixed fuel in your chainsaw(s).

Final words on Mixing Oil and Gas

Today, you have learned how to mix fuel for your chainsaw. You know the correct ratio for most of the ones you will find out there. We linked to blending charts from various sources, as they can help significantly, especially when dealing with foreign made chainsaws that the units of measure are different.

Next, the wording about fuel mixing you find on websites and in the owner’s manuals can be confusing. We hope we have cleared that up for you. Also, we gave you a little insight into why the mixing of gas and oil process helps protect two-stroke engines.

Finally, we went over the benefits of using premixed fuel as it has a long shelf life, extend your chainsaw’s usable lifespan, and in some case’s doubles the warranty of the one you are buying.

So, your chainsaw should start easier, run better, and give you fewer headaches down the road with the info we have given you today.