For Stihl bar oil, use a real bar and chain oil, never motor oil or used oil. I run Stihl Platinum in every Stihl saw I own, all year round here in East Texas. Stihl’s rule for picking a grade is simple: summer-grade oil when it’s consistently above 50°F, winter-grade oil when it’s consistently below. Fill the bar oil tank every time you fill the gas tank.
That covers most of it. Below is what Stihl actually says about its bar oils, how to tell your saw is oiling, why a Stihl leaks a little bar oil when it sits, and why I don’t use substitutes.
Which Stihl bar oil to use
Stihl sells several bar and chain oils. Here’s what each is for, from Stihl’s own pages and manuals.
| Stihl oil | When to use it |
|---|---|
| Platinum Bar and Chain Oil | Warm weather, above 50°F. This is what I use. |
| Woodcutter Bar and Chain Oil | Warm weather. Stihl’s data sheets give it the same thickness range as Platinum. |
| Winter Bar and Chain Oil | Below 50°F. Thinner, so it still flows to the chain in the cold. |
| BioPlus | When you want a rapidly biodegradable oil. Stihl’s MS 231/251 manual recommends it. |
Stihl says its winter oil is made to stick to the bar and chain and help keep sap and pitch from clinging, and that it works in Stihl and all other brands of chainsaws.
I buy Platinum by the gallon. A quart is handy if you only cut a few times a year.
Stihl Platinum Bar and Chain Oil, 1 gallon (0781 516 5005)
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Stihl Platinum Bar and Chain Oil, 1 quart (0781 516 5003)
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What weight is Stihl bar oil?
Stihl doesn’t sell its bar oil by a motor-oil weight like 30 or 10W-30. What it publishes is the oil’s viscosity, a measure of how thick it is. On Stihl’s safety data sheets, Platinum and Woodcutter both measure 121 to 174 cSt at 104°F (40°C), and about 10 to 12 cSt at 212°F (100°C). That’s a thick, sticky oil, which is the point: it has to cling to a chain moving very fast.
Winter oil is thinner on purpose. Stihl says summer-grade oil is much thicker and made for temperatures consistently above 50°F, and winter-grade is much thinner for temperatures consistently below 50°F.
Summer or winter bar oil?
Go by Stihl’s 50°F line. If you’re cutting in weather that stays below 50°F, switch to winter oil so it still reaches the chain. If you’re cutting above it, use summer grade.
Our winters in East Texas are mild, and most of my cutting happens on days above that line. I run Platinum all year and have never had an oiling problem. If you’re up north and cutting firewood in the cold, keep a jug of winter oil for those months.
How much bar oil does a Stihl use?
The MS 251’s oil tank holds 0.2 liters, about 6.8 ounces. Stihl’s instruction is to refill the chain oil tank every time you refuel. Make it a habit: gas and bar oil together, every time.
Stihl also says there should still be a small amount of oil left in the oil tank when the fuel tank runs empty. If your bar oil runs out before your gas does, or the oil level doesn’t go down at all, something’s wrong with the oiling. See the next section.
How to tell your saw is oiling
- Watch the oil tank. It should go down as you cut. If it stays full after a tank of gas, the oil isn’t getting to the chain.
- Look at the chain. Stihl says the saw chain must always spin off a small amount of oil while it runs.
- If the chain looks dry, stop cutting and find out why before you go on.
Stihl says never to run a saw without chain lubrication, because a dry chain and bar can be damaged very quickly. If the oil level isn’t dropping, Stihl’s manual says to check the chain lubrication, clean the oilways, and contact your dealer if needed. That last part matters while your saw is under warranty.
Shut the engine off and set the chain brake before you check the oil, fill the tank or touch the chain.
Why your Stihl leaks bar oil
A little oil under the bar after you’ve been cutting is normal. Stihl explains it like this: the oil circulating inside the bar rails, about .3 to .5 ounce, drains down by gravity once the chain stops, and seeps out under the bar and sprocket. Bar oil is thick and sticky, so it can keep seeping slowly for a few days.
If it’s still seeping after several days, Stihl points to the oil tank’s small vacuum relief valve. It’s a little silver disk with a hole in the center, on the side of the engine housing between the oil outlet and the bar studs. Debris can stop it sealing. Stihl’s fix is to push a small pin or needle into the hole six or seven times to clear it. If that doesn’t stop it, take it to your dealer.
My MS 251 doesn’t leak. My MS 230 sometimes does, but it’s an older saw.
Can you use a substitute for Stihl bar oil?
I wouldn’t, and I don’t. Stihl says the life of your chain and bar depends on the quality of the lubricant, so use a specially formulated chain lubricant. Stihl’s MS 231/251 manual is blunt about used motor oil: don’t use waste oil. Stihl says it doesn’t have the lubricating properties a chain needs, it’s harmful to the environment, and repeated skin contact with it can cause skin cancer.
I’m no oil expert, and I don’t pretend to know all the ins and outs. I stick with Stihl oils in my Stihl saws so there’s never a question if I need warranty work.
If you’re still choosing a saw, start with our gas chainsaw buying guide. For the gas side of things, see my Stihl chainsaw fuel mix guide, and for chains, my Stihl MS 251 chain size guide.
Stihl bar oil FAQ
What type of bar oil does a Stihl chainsaw use?
A bar and chain oil made for chainsaws. Stihl’s own are Platinum and Woodcutter for warm weather, Winter for below 50°F, and BioPlus if you want a rapidly biodegradable oil.
What weight is Stihl bar oil?
Stihl doesn’t give it a motor-oil weight. Its data sheets list Platinum and Woodcutter at 121 to 174 cSt at 40°C, a thick, tacky oil. Winter oil is much thinner.
Do you have to use Stihl bar oil in a Stihl chainsaw?
Stihl says to use a specially formulated chain lubricant, because the life of the bar and chain depends on it. I use Stihl’s own in my Stihls so there’s never a question about warranty work.
What can I use instead of Stihl bar and chain oil?
Another quality bar and chain oil made for chainsaws. Don’t use used motor oil: Stihl’s manual says waste oil doesn’t have the lubricating properties a chain needs.
Can I use motor oil like 20W-50 for chainsaw bar oil?
I wouldn’t. Stihl says to use a specially formulated chain lubricant. Bar oil is made thick and tacky to cling to a fast-moving chain.
When should I use winter bar oil?
When you’re cutting in temperatures consistently below 50°F. Stihl’s winter oil is much thinner so it still flows to the chain in the cold.
How much bar oil does a chainsaw use?
About one tank of bar oil per tank of gas. Stihl says to refill the oil tank every time you refuel, and there should still be a little oil left when the fuel runs out.
Where do you put bar oil in a Stihl chainsaw?
In the chain oil tank, not the fuel tank. Your manual shows which cap is which by its symbol. Clean around the cap before you open it so no dirt falls in, and don’t overfill.
Why is my Stihl chainsaw leaking bar oil?
Some seeping after cutting is normal: oil inside the bar drains down when the chain stops. If it keeps seeping for days, Stihl says to clear the small vacuum relief valve with a pin, or see your dealer.
Why is my Stihl not oiling the chain?
Check that the oil level drops as you cut. If it doesn’t, Stihl’s manual says to clean the oilways and see your dealer if needed. Never keep cutting with a dry chain.
Sources
Every source below was opened and checked on 2 October 2026.
- Fuel-Related FAQs: winter vs summer bar oil, 50°F (Stihl USA)
- Chainsaw FAQ: why a saw leaks bar oil, vacuum relief valve (Stihl USA)
- Winter Bar and Chain Oil (Stihl USA)
- Platinum Bar and Chain Oil safety data sheet: viscosity, part numbers (Stihl USA, PDF)
- Woodcutter Bar and Chain Oil safety data sheet: viscosity (Stihl USA, PDF)
- MS 231, 251 Instruction Manual: chain lubricant, filling, checking lubrication, oil tank capacity (Stihl, PDF)
- Find a Stihl dealer (Stihl USA)
