75w90 vs 75w140: Which One To Go For? [Answered]

If you have an automobile, you’re most likely to know about 75w90 and 75w140. But the problem is, almost everyone mixes them up and can not differentiate. In reality, these two are different with different attributes!

This dilemma confuses people in terms of picking one. But we’ll answer it for you!

Which one to use between 75w90 vs 75w140?

75w90 is a bit expensive compared to other gear oils and 75w140. But the quality of the additives is great for 75w90. When it comes to density, 75w140 has a scale of 0.89 whereas 75w90 has 0.86.

This is just a brief of what you are looking for! So, don’t stop just here because we’ve got the whole discussion ready for you.

Get started without wasting a second!

75w90 vs 75w140: Notable Differences

A detailed guide is absolutely necessary for comparison. However, a brief comparison would be great to an ideal start off! So, take a look at the table below to get a primary idea.

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75w90 vs 75w140: Everything You Need To Know

Coming across the table of comparisons, you already have an idea about their attributes. However, a single table might not be enough for you to understand their features properly. So, we have got a detailed discussion waiting you- 


Pricing of a product is the first thing that comes to our mind. So we had to talk about this first. When it comes to cost, which one should you choose between 75w140 and 75w90?

75w90 gear oil is currently a tad pricey on the market. You’ll have to spend roughly $10 for a liter of 75w90. As a result, users may find it difficult to purchase frequently.

Because it’s a balanced oil, this gear oil is more expensive than the others. So if you’re seeking the perfect balance, it’s worth it.

75w140, on the other hand, is significantly less expensive than 75w90. A liter of this gear oil would cost only about $2. You see, this oil is quite reasonable and cost-effective to use at any time.

Winner: In terms of pricing, we would like to choose 75w140 over 75w90. Because 75w140 is way more reasonable to use for automobile users.


In heavy-duty applications, 75w90 gear oil is highly smooth and trustworthy. Other lubricants aren’t quite enough for the machinery. It features an adhesive backing that coats gears and prevents squeezing.

The majority of gear lubricants, on the contrary, are just not strong enough to handle the stress. This gear oil has been designed to endure extreme temperatures while still lubricating properly.

The 75w140, on the other hand, includes anti-wear and lubricant additives. It helps with wear and tear management as well as heat control additives.

Typical gear oils don’t have these qualities. And this oil is highly recommended for all types of racing cars.

Winner: So, which one to use between 75w140 and 75w90 for better additives? Well, as per our evaluation, 75w90 comes first in terms of additives. Because it can outstand a great impact of gear strain.


The density of oil is a measurement of its thickness. Both 75w90 and 75w140 have a density that is identical to each other. Their density, however, is not the same.

75w90 has a density of 0.86. When compared to other oils, the density of this one is rather high. The higher the oil density, the better.

When compared to the thinner oils, this one does a good job of protecting the ears.

Thicker oils, on the other hand, can get clumpy, reducing efficiency greatly.

The density of 75w140 gear oil is higher than 75w90. It has a density of 0.90 grams per cubic meter.

As a result, it’s a little thicker, which helps to protect the ears even more. However, if this becomes clumpy, it may be difficult to operate the equipment effectively.

Winner: When it comes to the density, 75w140 is our first choice. Because it has relatively a greater density than 75w90. So, now you know if 75w90 is better than 75w140 or not in terms of density.

Can I Use 75w140 Instead of 75w90?

You may still be perplexed by the overall assessment. Don’t be startled buddy, we’re here to make your job easier.

By going through the comparison above, we suggest you go for 75w90 if you want more additives. However, if price and density are more important to you, you can use 75w140 instead of 75w90!

75w140 will provide protection to your car engine due to the extra density. But if your car needs thinner oil, it’s best not to use 75w140 instead of 75w90.

What Happens If I Put 75w90 Instead of 75w140?

75w90 is a thinner oil type than 75w140. Due to this, if you use 75w90 instead of 75w140, your engine will have less friction and operate easily. You won’t have any oil clogs during winter as well. So, these are some massive benefits.

However, thicker oil provides extra protection to the car engine. Thus, with 75w90, you’ll lack that extra protection.

Can I Mix 75w90 and 75w140?

Yes, you can absolutely mix 75w90 and 75w140. You won’t face any serious downsides. Instead this way you’ll be just balancing your engine oil. By mixing 75w90 with 75w140, you’ll have an engine oil that can provide both protection and efficiency. 

So, yes, you can try mixing them if you want better results!

That’s all there is to it when it comes to 75w90 vs 80w90. We hope you found this information useful!


Question: Are the transmission oil and gear oil the same?

Answer: Transmission oil is identical to gear oil in terms of characteristics. It lubricates the transmission as well as the gears. It is, however, used to lubricate the entire powertrain, including the gearbox and the prop shaft. The clutch and final drive shafts can also be lubricated using it. The term “transmission oil” is also used to describe lubricants. It’s called ATF, and it’s made especially for automatic gearboxes.

Question: Does thicker oil give more advantages to the automobile?

Answer: High viscosity lubricants are recommended for low-speed, loaded gears with a rough surface. A thicker coating with a higher viscosity has higher wear resistance. Furthermore, higher viscosity results in less gear deformation over time. In contrast to that, low viscosity oils are ideal for high-speed, low-load systems.

Question: Can I mix gear oil?

Answer: Mineral oils, PAOs, and esters are all compatible with one other. Synthetic lubricants of the poly glycol type (PG or PAG) are the only ones that cannot be blended with the other lubricant kinds. In the casings, they can react and create gum gels. They can also be incompatible and immiscible with other poly glycols at times.

The Final Words

Now you know which one to use between 75w90 vs 75w140! Both of them are great as gear oil of automobiles!

We hope our information helped you differentiate them. We believe you can make your final decision now!

Best wishes!

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