85w140 gear oil vs 80w90: What To Choose?

Gear oil works as a lubricant and prevents the gear from wearing out. You can’t get better performance from your car if you don’t use the correct oil. Both 85w 140 and 80w 90 are two fabulous gear oils for your car.

But which one is better, 85w 140 gear oil vs 80w 90?

85w 90 is a low viscosity gear oil. Its thin fluid reduces friction in a colder situation. But the 85w 140 is thicker and comparatively suitable for hot temperatures. Moreover, 80w 90 has -30 pour points that help the synthetic oil to operate effortlessly. Contradictorily, 85w 140 has -18 pour points.

Anyways, this was just a sneak peek. We’ve prepared a head-to-head comparison of both gear oils. 

Let’s have a look-

What Do 85w140 and 80w90 Mean?

First, we need to understand what 85w 140 gear oil and 80w 90 stand for. Knowing this will make this comparison significantly easier for you.

The numbers of the oil types are universally considered as an oil grading system. The word “W” in the center actually refers to Winter. So yeah it doesn’t mean weight.

Now, as you can see there are two numbers beside the word W. Well, the numbers basically refer to the viscosity the two oil types will provide. 

And they will offer these viscosity amounts in different temperatures. That’s why the numbers aren’t the same. 

Still, confused? 

Well, break it down-

In the case of 80w 90, the first number “80” means the gear oil will work good in lower temperatures. Then the number “90” refers to the viscosity of this gear oil at 100° C or higher temperatures. 

The description is the same for 85w 140. 

80w90 VS 85w140: A Heads Up

A head-to-head comparison helps us understand their similarities and differences. Both 85w 140 and 80w 90 gear oils have some effective features. We have prepared a chart below. Here we’ll showcase the features to illustrate a full picture.

This chart will make your decision process easier. Because you can figure out the distinctions clearly. So, let’s have a look-

Features85w 14080w 90
Viscosity rateHigherLower
Synthetic FormulaHighAverage
Pour Point-18°-30°
Suitable VehiclesHeavy VehiclesRegular vehicles

This chart can work as a direction to decide which oil your car needs. But if you are interested in knowing these features a little broadly, read along with us.

85w 140 VS 80w 90: Detailed Comparison

It’s time to check the detailed comparison to understand better. This way you can be sure of your decision and won’t regret it later. 

Viscosity & Thickness

Viscosity rating measures the resistance of the oil flow. Higher the viscosity, slower the flow. A higher viscosity rating indicates less smoothness of your engine’s friction.

The viscosity of your gear oils is remarked as a compromise. This compromise is eligible between the gear parameters requiring low viscosity and those requiring higher viscosity. The viscosity of fear oils relies on the temperature.

Hence, you must select the gear oil that fulfills the requirements of your gear. Gear oil must reach the expected temperature range of your particular gear.

Between 85w 140 and 80w 90, the first one has a higher viscosity rate. Both the first and last number of the 85w 140 gear oil is higher than 80w 90. Therefore, 85w 140 has a higher viscosity than 80w 90 in both cold and hot weather.

The viscosity chart rates 80w 90 gear oil up to 95 degrees. Whereas the gear oil 85w 140 is rated to 120 degrees.

As a result, 80w 90 is thinner. That means, its flowing resistance is comparatively less than the other.

Whereas, 85w 140 is thicker. It’s slightly more efficient and suitable for heavy vehicles.

Pour Point

Pour point of an oil is the lowest temperature at which it can flow by gravity. After crossing this limit the oil won’t move on its own. Pour points are directly connected with viscosity rating.

Pour point indicates the fluid’s lowest temperature properties. When the surrounding temperature is lesser than the pour point, it will get stuck inside the pipeline. The 85w 140 can bear up to -18 degrees celsius. That means, its pour point consistency can reach up to this temperature.

Whereas, the 80w 90 can be much more capable than the previous one. It has a capacity of -30 degrees celsius of pour point. This gear oil is accurate for cold temperature regions.

Synthetic Level

Synthetic gear oils are generally applied when the gear oil achieves its performance limit. Further, it can’t meet the application requirements. In this situation, synthetic gear oil takes the lead.

Synthetic gear oils are most suitable under some physical properties. For example, thermal resistance, flashpoint, and mostly low temperatures properties. Low-temperature properties include fluidity and pour points. Both the oil types mentioned here are full synthetic oil.

However, there’s a slight difference in their performance. Because the lower the pour points are, the more synthetic formula will work. As a result, 80w 90 works slightly better. 

Suitable Vehicles

Different types of vehicles require different gear oils. 85w 140 gear oil suitable for heavy vehicles like trucks, vans, buses. Because this gear oil is specialized for lower viscosity vehicles. Vehicles with high speed and loaded with heavyweights are ideal for 85w 140 oil.

Whereas, 80w 90 is applicable for both heavy and regular vehicles. This gear oil has a higher viscosity rating that helps the fluid to flow slowly. This oil is appropriate for comparatively warm temperatures.

So, these were all the differences between them. Pick the suitable gear oil based on these differences and your vehicle.

Can I Use 80w 90 Instead of 85w 140?

We highly suggest using the oil that is recommended in your car manual. But you might want to interchange between these two oil types. So, here are a few things you should know-

Well, when you’re already using the 85w 140, shifting to 80w 90 will be a bad decision. Because your car requires a higher viscosity level. The 80w 90 won’t fulfill this requirement. As a result, this can affect your gearbox.

Simply put, going lower on operating viscosity will be objectively bad for your car. Also, going higher from 85w 140 may severely damage your engine during winter.

What Happens if I Put 85w 140 instead of 80w 90?

If you’re already using 80w 90 oil, you don’t need to shift to 85w 140. As 80w is worthy enough for both heavy and regular motors. Thus, using 80w 90 will be good enough for your vehicle.

But still, We suggest you use 85w 140 instead of 80w 90. Because it provides more protection. But if you live in a really cold region, 80w 90 is the way to go.

Can I Mix 85w 140 and 80w 90?

Yes, it’s possible to mix the two oil types. Your engine isn’t that picky about this situation.

If you mix these two oil types, the result won’t be that impactful. Because you’re just thickening the thinner oil type and thinning the thicker oil type. As a result, you’re just balancing out the oil’s thickness. 

Therefore, you mix them together. 


Question: What is SAE 140 gear oil?

Answer: A SAE class 140 gear oil is high-quality mineral oil. These oils are somewhat additive. SAE 140 transmission gear oil can consistently maintain its quality level. They are suitable for older version cars as well as classic motorcycles.

Question: Is thicker gear oil better?

Answer: Thicker gear oils are most efficient for low speed. Vehicles with loaded gears with a rough surface are perfect for thicker oil. Higher viscosity gives a thick film, more wear resistance. As well as it provides less deformation of gears as time flies.

Question: What happens if you use the wrong gearbox oil?

Answer: The wrong gearbox oil can cause multiple issues to your car. Most likely poor lubrication, overheating issues or even transmission failure can happen anytime. A mechanic won’t be able to rescue your gearbox from the damage that occurred.

Question: What is 90 weight gear oil used for?

Answer: A 90 weight gear oil is applicable for extreme pressure situations. This oil is for colder climates and is used mostly for limited-slip differentials. Moreover, its use in heavy-duty manual transmissions, final drives, and axles.


So, that’s all we could manage regarding 85w 140 gear oil vs 80w 90. We hope the comparison helped you, even if it’s a little bit.

So, have you decided which oil you are going to use? 

We hope you’ll go through all the features of each oil. Then pick the one that suits your car engine the best.

Have a good day!

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