Can I Use 10W-40 for Chainsaw Bar Oil? (Must Read!)

Have you ever found yourself in a situation where you ran out of chainsaw bar oil and wondered if you could use 10W-40 motor oil instead?

If you have, then you’re not alone. It’s a common question among chainsaw owners and operators.

Here’s a quick answer:

Yes, you can use 10W-40 motor oils for chainsaw bar oil in a pinch. But, they may not be as effective as standard chainsaw bar oils. They are not “tacky” enough and tend to sling off quickly when the chain is moving fast.

Btw, I’m Sam and I’ve been using chainsaws for more than two decades now. In this article, we’ll discuss everything you need to know about using 10W-40 motor oil for chainsaw bar oils.

So, let’s dive in!

What Does "10W-40" Mean?

can i use 10w-40 for chainsaw bar oil

So, you see that confusing combination of numbers & letters on your motor oil bottle and you have no idea what it means.

It’s actually quite simple! Think of it as a code that tells you the “viscosity” of the oil & how the oil will perform in different temperatures.

Let me make it even simpler for you!

Viscosity refers to how easily the oil flows. A low-viscosity oil will flow more easily than a high-viscosity oil.

And to indicate viscosity, the SAE (Society of Automotive Engineers) developed a grading scale that ranges from 0W (the thinnest) to 60 (the thickest). 

They’ve further introduced a multi-grade scale (xW-xx), as we see in “10W-40”.

While single-grade oils (like 10W, 20W) are designed for a specific temperature range, multi-grade oils (like 10W-40, 15W-50) can perform well in both cold and hot temperatures. 

Now, let’s decode “10W-40“.

The “10W” part means the oil will act like a 10 grade (thin & fluid) when the engine is cold, so your engine quickly gets the lubrication it needs when you start it.

On the other hand, the “40” tells us that the oil will act like a 40 grade (thick & protective) when the engine is hot without thinning out too much.

10W-40 VS 10W-30 Motor Oils

Well, both these oils are multi-grades and start with “10W”. So, they provide the same level of protection when things are chilly. It’s the ’30’ and ’40’ part where things change.

The ’30’ in 10W-30 means it’s a little less thick at higher temperatures than the ’40’ in 10W-40.

Btw, I’ve written an entire article on using 10W-30 motor oils as an alternative to chainsaw bar oils! You can check that out if you’re interested.

What Grade is Chainsaw Bar Oil?

When it comes to chainsaw bar & chain oils, they are mainly divided into 3 categories depending on their viscosity:

  • Summer:  40W, 50W
  • All-seasons: 30W (Standard)
  • Winter: 10W, 20W

30W is the standard grade for chainsaw bar oils and it does the job well in most temperatures.  Frankly speaking, this is what you’ll find in most stores.

But if you’re living in a place where winters are harsh or summers are scorching, you need to pick a higher or lower viscosity oil respectively.

Are There Multi-Graded Chainsaw Bar Oils?

No, you won’t find multi-graded chainsaw bar oils like 10W-40 or 10W-30. These are specifically designed for engines and for a good reason.

When you start an engine, the oil needs to flow quickly to provide lubrication to the parts and the low viscosity (10W) helps it do just that.

And when the engine is hot, the oil needs to hold its viscosity without thinning too much. That’s where the high viscosity (40, 30) comes in.

But with chainsaw bar oils, the oil’s job is different.

They are designed to provide constant lubrication to the bar & chain, regardless of the amount of heat being generated.

Btw, here are 3 chainsaw bar & chain oils that I use and recommend:

You can find these at your local retailer or online!

Can You Use 10W-40 Motor Oil for Chainsaw Bar Oil?

YES, you can use 10W-40 motor oils for chainsaw bar oil. If you’re in a pinch and you’ve got some 10W-40 motor oil hanging around, you could use it as an alternative for chainsaw bar oil.

To be honest, I’ve personally used 10W-40 in my chainsaw before and it worked just fine. No performance issues whatsoever.

But here’s the catch!

Chainsaw bar oils are specially formulated to provide the necessary lubrication to the bar & chain.

They contain special additives that give them a “tacky” or “clingy” texture. This helps the oil to stick to the bar & chain better, providing constant lubrication, even at high speeds.

But 10W-40 motor oils, on the other hand, do not have these additives. They lack the “tackiness” and tend to sling off the chain faster. 

Plus, compared to standard chainsaw bar oils (30W), 10W-40 motor oils are thinner.

So, while you can technically use 10W-40 motor oil as a substitute for chainsaw bar oil, I still consider it as a temporary solution. (Something is better than nothing, right?)

Are 10W-40 Motor Oils BAD for Your Chainsaw?

It would be wrong if I just said “yes” or “no”.

So here’s the thing:

10W-40 motor oils do provide lubrication to your chainsaw in a pinch. It’ll help you get the job done, but it may not be as effective as standard chainsaw bar oils in the long run.

And if you’re talking about “used” 10W-40 motor oils, then it’s a strict “NO” from me!

Used motor oils contain microscopic carbon & metal particles that can act as abrasives and eat away at your saw’s bar, chain, and sprocket.

On top of that, used motor oils are already broken down, so they’ll sling off the bar & chain even more quickly.

Plus, it’s not environmentally friendly either!

So, it’s better to stick with standard chainsaw bar oils or at least use new 10W-40 motor oil if you’re in a pinch. 

But don’t make it a regular practice! Your chainsaw will thank you for it.

What Else Can I Use as Chainsaw Bar Oil?

Let’s assume that you’re out of chainsaw bar oil and somehow 10W-40 motor oil is also not available. What do you do?

Well, in that case, here are a few options that you can use as a substitute for chainsaw bar oil:

  • Canola Oil: It has a similar viscosity to standard bar oils. Plus, it’s cheap, eco-friendly, and readily available in your kitchen. But, it tends to sling off way faster than other options on this list. So, be ready to top up your oil tank more often.
  • Motorcycle Chain Oil: It has a higher tackiness and GOOD lubrication properties.
  • Gear Oil or Transmission Fluid: These are thicker than standard chainsaw bar oils but can still work in a pinch.
  • Automotive Oil: Just like 10W-40 motor oils, you can use automotive oils (for example, 5W-30 or 10W-30) as substitutes for bar oils.

Can You Run a Chainsaw Without Bar Oil?

Running a chainsaw without bar oil = Recipe for Disaster!

Seriously, don’t even think about it!

The bar and chain are both made of steel. And the only job of chainsaw bar oil is to provide lubrication to the chain so that it doesn’t heat up and break.

But, when there’s no bar oil (or not enough of it), the friction between the chain and bar generates a lot of heat. This may cause the chain to overheat, warp or even break mid-use.

The bar, sprocket, and clutch are also at risk of getting damaged.

So, before starting your chainsaw, always make sure that you have enough oil in the tank.

Chainsaw not oiling? Then here’s how you can fix it!

Samuel Anali

Hey there! My name is Sam, and I'm the NERD behind this site. I'm an avid chainsaw enthusiast, and I've been tinkering with them since I was 17 (it's almost 20 years now!).

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