Can You Use 50 To 1 In 40 To 1? Detailed Explanation. STIHL chainsaw oil mix

STIHL chainsaw oil mix

1 litre STIHL HP Ultra 2 stroke engine oil with measure(makes 50 Litres of 2 stroke)

Stihls highest quality fully synthetic oil, designed for long periods of use under the most demanding conditions.

This high quality oil with exceptional lubrication properties, low-residue combustion, more than 80% biodegradable in 3 weeks, it is particularly low in sulphur,

Performance class certification JASO-FB, ISO-L-EGB.

This is usually mixed at a Fuel/oil ratio 50:1.but best to check with manufacturers model recommended mix ratio.

STIHL Part Number 0781 319 8061

for search STIHL ultra oil, STIHL HP ultra, STIHL fully synthetic oil, STIHL 2 stroke mix, 07813198061, STIHL 07813198061, STIHL ultra mix, STIHL HP ultra oil, 1 litres STIHL oil, is owned and run by the parent group International Systems Equipment. Our existing knowledge of current markets allows us to provide a one-stop shop for parts service kits for all your garden machinery needs, at excellent factory direct prices.

Get in touch

Please submit your product inquiry to the form below and we will get back to you as soon as possible during our office hours 9am to 5pm (GMT) Monday to Friday

Your can email us at

or 24 hour a day international Whatsapp Text Message on 353860753729

Contact Us

Add Connect on Social Media

Thanks for your inquiry! We will get back to you shortly!

Privacy Preference Center

When you visit any website, it may store or retrieve information on your browser, mostly in the form of cookies. This information might be about you, your preferences or your device and is mostly used to make the site work as you expect it to. The information does not usually directly identify you, but it can give you a more personalized web experience. Because we respect your right to privacy, you can choose not to allow some types of cookies. Click on the different category headings to find out more and change our default settings. However, blocking some types of cookies may impact your experience of the site and the services we are able to offer.

Manage Consent Preferences

These cookies are necessary for the website to function and cannot be switched off in our systems. They are usually only set in response to actions made by you which amount to a request for services, such as setting your privacy preferences, logging in or filling in forms. You can set your browser to block or alert you about these cookies, but some parts of the site will not then work. These cookies do not store any personally identifiable information.

These cookies allow us to count visits and traffic sources so we can measure and improve the performance of our site. They help us to know which pages are the most and least popular and see how visitors move around the site. All information these cookies collect is aggregated and therefore anonymous. If you do not allow these cookies we will not know when you have visited our site, and will not be able to monitor its performance.

These cookies enable the website to provide enhanced functionality and personalisation. They may be set by us or by third party providers whose services we have added to our pages. If you do not allow these cookies then some or all of these services may not function properly.

These cookies may be set through our site by our advertising partners. They may be used by those companies to build a profile of your interests and show you relevant adverts on other sites. They do not store directly personal information, but are based on uniquely identifying your browser and internet device. If you do not allow these cookies, you will experience less targeted advertising.

By clicking “Accept All Cookies”, you agree to the storing of cookies on your device to enhance site navigation, analyse site usage, and assist in our marketing efforts. Cookie Policy

detailed, explanation, stihl, chainsaw

Can You Use 50 To 1 In 40 To 1? [Detailed Explanation]

Are you confused about using a fuel mixer on your chainsaw? This can be especially true when you buy an old chainsaw and don’t know what type of fuel mixer the manufacturer recommends using.

Modern chainsaw engines are usually 2-cycled, 2-stroke. Most companies recommend using a 50 to 1 or 40 to 1 fuel mixer in this type of engine. But for those who are unsure about the specific recommendations of the company, the question comes from them; can I use 50 to 1 in 40 to 1?

Yes, you can use 50 to 1 instead of 40 to 1 fuel mix to your chainsaw. Although in uncertain situations one should go for a mixer with higher oil content, a 50-to-1 mixer can improve the chainsaw’s engine performance. For this reason, many experts recommend a 50 to 1 fuel ratio.

Here, I will discuss the fuel ratios used in chainsaws. If you want to know about using the right fuel mixer for chainsaws, this article is for you. Let us dive deeper into the article by understanding both fuel mixers.

What Is The 50 to 1 And 40 To 1 Ratio Oil Mixture Actually?

A 50 to 1 or 50:1 ratio oil mixer refers to a mixture of 50 parts gasoline and 1 part oil. It is relatively light and helps the 2-stroke engine to run more efficiently. Many chainsaw manufacturers recommend this mixer for their best chainsaws.

Besides, a 40 to 1 or 40:1 ratio oil mixture refers to a mixture of 40 parts gasoline and 1 part oil. This fuel ratio is a little thicker than the 50:1 blend. As a result, it generates somewhat less heat, helping chainsaws run more smoothly. As a result, this fuel ratio is more popular.

What Is The Difference Between 40:1 And 50:1 Gas Mixture?

The fundamental difference between both gas mixtures is the density of the fuel. A 40:1 oil mixture ratio is slightly thicker. It generates less heat and results in less piston wear. 40 to 1 oil mixture is better for operating the chainsaw for a long time.

A 50:1 gas mixture is slightly lighter than a 40:1 ratio. It generates a little more heat and wears the piston more. But the advantage of this fuel ratio is that it increases the efficiency of the engine even more. However, fuel consumption is also high in this ratio.

Why Does 2-Cycle Engine Require A Mixture Of Gasoline And Oil?

2-cycle engines complete two cycles in one revolution of the crankshaft. Besides, if we consider the working method of a 4-cycle engine, it completes its four cycles by 2 crankshaft revolutions. 2-stroke power engines have relatively fewer moving parts, making them lighter and stronger.

4-cycle engines include a separate oil pump as a lubrication method that takes power from the engine. This pump helps reaches engine oil through belts and pulleys to the moving parts and lubricates them. That’s why those moving parts run smoothly, and the engine stays cool.

But, 2-cycle engines do not have a separate oil pump like 4-cycle engines. Although this makes it convenient to mount them in any position and even upside down, a lubricating system remains lacking.

A mixture of gasoline and oil acts as a fuel as well as a lubricant. This type of mixture prevents excess heat generation. Therefore, 2-cycle chainsaw engines always use a mixture of gasoline and oil.

Is It Ok To Use 40 To 1 Fuel In 50 To 1 Engine?

Yes, you can use a 40:1 oil mixture in a 50:1 engine with no hesitation. Although there is some variation in density at both fuel ratios, it is tiny and worth neglecting. Also, this 40 to 1 ratio will help keep your chainsaw’s engine relatively cool and last longer. A ratio of 40:1 instead of 50:1 may be ideal for you, especially if you want to save fuel.

What Oil Ratio Is Better For A 2-Cycle Chainsaw Engine?

Honestly speaking, both 50:1 and 40:1 oil ratios are best for different types of chainsaws engines. But the selection of oil ratio will depend on your requirement or satisfaction. That is, in different situations, oils with different ratios can give you more benefits.

When you need more power from the engine or need to operate the chainsaw at higher rpm, use a 50:1 oil ratio. Since this ratio is lighter, the performance of the engine will also improve.

Also, when you need to operate the chainsaw with fuel economy at average rpm, 40:1 may be the best choice for you. As this oil ratio makes the engine less hot and saves fuel, you can work for longer hours without interruption.

How To Make 40 To 1 And 50 To 1 Oil Mixture?

40 to 1 ratio or 50 to 1 oil ratio is very easy to make. You will need ethanol-free gas, synthetic oil, a measuring cup, and an empty gas can. I will describe here how to make both of these oil mixtures. According to this ratio, you can make your required amount of oil mixture.

To make a 40:1 ratio, use one gallon of gas and 3.2 oz of synthetic oil. Similarly, you will need 8 oz of oil with 2.5 gallons of gas. Measure the correct amount of gas and oil into the empty gas can using a measuring cup.

Now close the gas can and shake it well. Keep shaking until both ingredients are well mixed. When the ingredients are mixed well, your oil mixture is ready to use.

You should follow the same procedure to make a 50 to 1 ratio oil mixture, only the ratio of gas to oil will be different. This ratio requires you to use 2.6 oz of oil per gallon of gas. In the same way, you will need 6.4 oz of synthetic oil for 2.5 gallons of gas.

What Has Oil; 40 To 1 Or 50 To 1?

A 40 to 1 ratio contains more oil than a 50 to 1 ratio. Whereas, a 40 to 1 ratio contains one gallon of gasoline with 3.2 ounces of oil, a 50 to 1 ratio contains about 2.6 ounces of oil.

detailed, explanation, stihl, chainsaw

What Is The Problem With Using Regular Gas In A Chainsaw?

The problem with using regular gas on a chainsaw is that it tends to overheat the engine. Because of this, the engine wears down quickly and can even be completely damaged. Also, since these engines are 2 cycles and have no separate lubrication system, the engine cannot run smoothly using only gas.

What Kind Of Oil Should You Mix With Gas For A Chainsaw?

Experts recommend always mixing synthetic oil with gas for chainsaws. Since the oil has to operate at high temperatures, conventional oils may not perform well. On the other hand, quality synthetic oils help the engine run smoothly.

Final Thoughts About Using 50 to 1 in 40 to 1

Both 50 to 1 and 40 to 1 ratio oil mixtures are suitable fuels for your chainsaw’s 2-cycle, air-cooled engine. You can switch from one of these to the other at any time. You should use the oil ratio as per your requirement.

Earlier chainsaws used more varied oil ratios, such as 32:1 and even 16:1. But the history of chainsaw engines have improved a lot, which is why the recommendations for mixing ratios of the oils used in them have also changed.

Hopefully, I have cleared up all the confusion about using the right oil mixture for your chainsaw.

Hi, I am Jose Wilson. I am an avid DIY woodworker. I love to try out new woodworking tools. In over 25 years I have tried several Woodworking tools including Chainsaws, Circular saws, Table saws, and Jigsaws among the rest. I also learned that many people didn’t quite understand how to use these tools. I want to help peoples to learn the use, benefits, and how these woodworking tools operate. I have created a number of work-tools s, built websites, and developed social media pages. Follow me on my social media.

Inconsistent 2 stroke mixed gas Does every drop REALLY count? (Surprising test results found!!!)

One Solution for Different Two-Stroke Mix Ratios?

Two-stroke engines derive lubrication from the oil mixed directly into the gasoline, unlike your car engine, which lubricates itself with oil housed in an oil sump and circulated by an oil pump. Read more about the differences between two- and four-stroke engines.

detailed, explanation, stihl, chainsaw

Untangling different mix ratio recommendations and mixing multiple containers of fuel is a hassle, particularly for professionals who run several different pieces of equipment. What if there was one solution for different two-stroke oil mix ratios that worked in all your equipment?

The mix ratio is the proportion of gas to oil, expressed as a ratio. For example, 50:1 means 50 parts gas to 1 part oil.

Oil mix ratios explained

If your manufacturer recommends a 50:1 fuel/oil mix, it means you need 50 parts of gas to one part two-stroke oil. To mix one gallon of fuel at 50:1, add 2.6 ounces of two-stroke oil to one gallon of gas, as shown in the chart below. Don’t worry, we’re going to eliminate the need for a metric chart shortly.

Different mix ratios create confusion

Different equipment manufacturers recommend different oil mix ratios, complicating matters. Most modern chainsaws, string trimmers, leaf blowers and other small-engine two-stroke equipment recommend a 50:1 oil mix ratio, but some recommend 40:1 and older two-stroke equipment might even call for 32:1. Multiple pieces of equipment with different mix ratios would traditionally require mixing and storing multiple cans of fuel. That’s not only a hassle, but it’s also a recipe for misapplication.

This scenario can be a big problem for landscapers and other professionals who operate multiple pieces of equipment under heavy use. But plenty of homeowners also maintain older equipment that call for a richer fuel mixture. It would be so much easier if every manufacturer recommended the same mix ratio…

AMSOIL Performance Testing

Laboratory tested and proven on the road.

See how AMSOIL products perform in the lab and in the field.

One two-stroke mix ratio for all equipment

SABER Professional Synthetic 2-Stroke Oil has been thoroughly tested on two-stroke engines at any mix ratio up to 100:1. That means you can mix one can of fuel and use it in all your two-stroke equipment, regardless of the recommended mix ratio. You can still mix SABER Professional at a lower ratio, but for the best value, we recommend 100:1. It also makes metric calculations even easier, simply mix 10ml of SABER Professional per liter of fuel. Problem solved.

Even more benefits

The convenience of using one mix ratio for all your equipment means you’ll spend less on oil, reduce overall operational costs and help the environment. Older two-stroke engines were designed to run on the conventional oil with very few additives that was available decades ago, often at a 20:1 ratio, meaning 5% of your fuel was oil! AMSOIL SABER Professional Synthetic 2-Stroke Oil burns cleaner and better than oils made decades ago, so engines require less oil to generate combustion while maintaining lubrication, seal integrity and drastically reducing dirty oil-burning byproducts.

SABER Professional also delivers improved cleanliness mixed at 100:1 compared to other oils mixed at a conventional 50:1 ratio. For example, the spark-arrestor screen is especially prone to deposits since it’s positioned in the exhaust stream. Heavy deposits choke off airflow and lead to hard starting, rough running and power loss. As shown in the images above, equipment using SABER Professional remained 96% carbon-free based on spark-arrestor testing.

Check out this technical study that shows how SABER Professional performed against a competitor’s oil in Echo string trimmers. As the testing shows, it’s one of the best two-stroke oils available to protect your equipment. Still don’t believe it? Watch the following video from professionals in the field:

STIHL chainsaw oil mix

Spring 2019 STIHL provides professional users with the ideal outdoor power equipment solution, offering all the benefits of two-stroke and four-stroke engine technologies combined. Like the four-stroke and two-stroke engines, the STIHL 4-MIX /b> engine is an internal combustion engine. Energy is released during combustion of the fuel-air mixture in the cylinder, which is converted into motion via the piston and crankshaft. The carburetor supplies the correct mixture of air and fuel. The spark plug initiates combustion by producing an ignition spark at the exact predetermined point.


Unlike other four-stroke engines, the 4-MIX /b> engine is lubricated by the gasoline-oil mixture. As such, it must be run on a mixture of gasoline and engine oil. This allows a compact construction without a separate oil reservoir, oil pump and oil filter.

Like the time-proven STIHL two-stroke engines, the STIHL 4-MIX /b> engine operates reliably at any angle, even upside down. It is therefore very suitable for applications in STIHL portable power tools. The 4-MIX /b> engine is relatively quiet in operation and, like STIHL two-stroke engines, complies with the strict exhaust emission standards.


As the 4-MIX /b> engine makes use of the gasoline-oil mixture for lubrication, it combines the benefits of two-stroke and four-stroke engines.

  • Familiar fuel mixture ratio (50:1)
  • Operates in all positions
  • Cleaner. reduced emissions
  • power. high torque
  • Good acceleration. quick starts
  • Low fuel consumption
  • Favourable power-to-weight ratio
  • Compact construction. attractive design
  • Fewer vibrations
  • Low noise level


The crankshaft (5) rotates. The piston (4) moves down the cylinder. The inlet valve (3) is opened by the cam (not illustrated). Fresh fuel mixture flows through the inlet port (2) into the combustion chamber (6) until the inlet valve is closed again by the cam.

Unlike most other four-stroke engines, the valve gear (10) and crankcase (12) on the STIHL 4-MIX /b> engine are connected to the inlet port (2) via a bypass bore (9). This way, part of the fuel mixture constantly flows around all the moving parts (valve gear, crankshaft, cam, piston). This ensures lubrication of the 4-MIX /b> engine without a separate supply of engine oil.

The transfer of the fuel/engine oil and air mixture is controlled by the upward and downward movements of the piston (4).

Over-pressure is created in the crankcase (12) when the piston moves down the cylinder. This over-pressure forces mixture out of the crankcase (12) through the cam housing (not shown in the illustration), via the pushrod passages (11) and the valve gear (10), through the bypass bore (9) and inlet port (2) to the combustion chamber (6). All lubricating points are wetted in this process.


Both valves are closed. The piston (4) moves up the cylinder again and compresses the mixture. A depression is created in the crankcase (12) as the piston moves upwards. This depression sucks in the gasoline-oil mixture: it flows from the carburetor through the inlet port (2), via the bypass bore (9) to the valve gear (10) and the pushrod passages (11), through the cam housing to the crankcase (12). All lubricating points are wetted in this process.


Compression of the mixture is greatest when the piston (4) reaches its highest point in the cylinder (top dead centre or T.D.C.). The spark plug (1) initiates combustion of the mixture by producing an ignition spark. The piston is forced down the cylinder and produces power.

Note: To improve efficiency, the mixture is ignited just before T.D.C.

As the piston (4) moves down the cylinder the mixture is again forced out of the crankcase (12) through the cam housing, via the pushrod passages (11) and the valve gear (10) to the inlet port (2) (as on the induction stroke).


The cam opens the exhaust valve (7) before the piston (4) reaches its lowest position (bottom dead centre). During the following upward movement of the piston the spent gases are forced out of the combustion chamber (6) through the exhaust port (8). The cylinder is now clear and ready for the next induction stroke.

A depression is created in the crankcase (12) at the same time which sucks in the fuel/oil and air mixture so that it reaches all lubricating points (as on the induction stroke).


  • FS 91 / FS 91 R
  • FS 111 / FS 111 R / FS 111 RX
  • FS 131 / FS 131 R
  • BR 500 / BR 600 / BR 700 / BR 800 C-E / BR 800 X

What is the Correct Gas to Oil Mix for Chainsaws?

Chainsaws can be expensive machines, and if you own one, you are sure to want to keep it in good working order. If you have a gas-powered one, part of this will mean always using the correct fuel – and since most chainsaws are 2-stroke models, this will involve mixing up the right gas-and-oil mix.

What is the correct gas to oil ratio for chainsaws? Why do you need to mix gas and oil like this? And what happens if you don’t? Here, we have the answers to these questions and more to help you keep your chainsaw running the way you want it to.

If you want a quick preview of some of the stuff we’re going to be talking about, check out this video that introduces some of the main concepts.

Before we get into mixing oil for your chainsaw’s fuel tank, let’s take a step back and think about why we need to do this at all.

Chainsaw engines come as either 2-stroke or 4-stroke versions. Sometimes these are also referred to as 2-cycle and 4-cycle engines – it’s the same thing.

Without going deep into the mechanics of how chainsaw engines work, a 2-stroke engine produces power for every two strokes of the pistons while a 4-stroke engine requires four strokes to produce power.

In a 4-stroke engine, on the third stroke, oil is taken from a special oil reservoir and brought into the engine to lubricate it. Since there is a separate oil reservoir and a stroke dedicated to lubrication, there is no need to mix oil into the gas the engine runs on.

However, in a 2-stroke engine, this doesn’t happen. There is no separate oil reservoir and there is no stroke dedicated to the lubrication of the engine – and for this reason, to keep a 2-stroke engine running smoothly, oil needs to be added to the fuel.

What is the Correct Gas to Oil Mix for Chainsaws?

There is no standard oil-to-gas ratio across engines, and you will need to check the manual for your particular chainsaw. However, most 2-stroke chainsaw engines, as well as any other similar power tools, run on a mixture that is one part oil to 50 parts gas, 1:50

However, many run on a ratio of 1:40, and other optimum ratios are possible – this is why it is essential to check the requirements of your machine.

So what does this look like in practice? Just to give an example, a 1:50 ratio of oil to gas works out at 2½oz of oil to each gallon of gas.

When you make your oil-and-gas mixture, take care to measure the amounts as precisely as possible. If you don’t get it right, you can easily end up damaging the engine of your chainsaw.

However, having said that, if you do make a mistake, it is better to have a little bit too much oil than not enough, so if in doubt, you can be slightly generous when adding the oil to the mix.

And what happens if you forget to add oil to the fuel you put in your chainsaw? You will know about it very quickly. The engine will start smoking within less than a minute and if you don’t shut it off immediately, it is likely to suffer irreparable damage.

detailed, explanation, stihl, chainsaw

Will my chainsaw last longer if I use more oil? Is it safer? (25:1 VS 50:1 temperature testing)

How to make a gas and oil mix

If you have a chainsaw with a 2-stroke engine, you can easily mix up your own gas-and-oil blend to use as fuel. There’s no special technique, and all you’ll need is a gas can and something to measure the volumes.

First, pour the required amount of gas into the gas can. Carefully measure out the required amount of oil and pour it in after. Close the cap on the gas can and give the whole thing a good shake to make sure the gas and oil are properly mixed.

You can now use the mixture in your gas can to fill up your chainsaw.

General tips about gas engines

If your chainsaw hasn’t been used for a while – say, for a couple of weeks but less than a month – give the whole thing a good shake before you fire it up. If you leave it sitting, the gas and oil will separate it, and shaking the chainsaw will ensure they are well mixed before you start it.

If you don’t use your chainsaw for more than a month, empty the fuel and refill it with fresh fuel. Gasoline doesn’t age well, and after a month it will begin deteriorating to the point where the chainsaw no longer functions correctly. If you try to use old fuel, you risk damaging your chainsaw’s engine.

If you don’t want to mix gas and oil yourself, you can buy premixed fuel to save yourself the hassle. If you do, make sure you choose one that is suitable for your machine.

Make sure you know what kind of engine your chainsaw has. If it is a 2-stroke engine and you forget the oil, you will damage the engine. However, if you have a 4-stroke engine, you should make sure you only use pure gas – otherwise, you will also risk damaging your expensive chainsaw.

Quite separately from engine oil, chainsaws need oil for chain lubrication. This is true of gas-powered versions as well as electric chainsaws and cordless chainsaws. Make sure you don’t forget to lubricate the chain.

Always use the right ratio

As we said, while the most common oil-to-gas ratios are 1:50 or 1:40, there is no standard, so you shouldn’t just guess. Make sure you find out exactly what ratio your chainsaw’s engine requires and mix it up carefully and precisely. Similarly – and this goes without saying – make sure you know whether you are running a 2-stroke engine or 4-stroke engine before filling the tank and firing it up.

Chainsaws are expensive tools, and failing to use the right oil-and-gas mix – or pure gasoline in the case of a 4-stroke engine – is the quickest way to send you valuable machine straight to the scrapyard.

Don’t forget to pin it!

| Denial of responsibility | Contacts |RSS | DE | EN | CZ