75w90 vs 80w90 Gear Oil

75w90 vs 80w90 Gear Oil

There are a few things in life as important as your car. It would be best if you got to work, take the kids to school, and run errands. That’s why it’s essential to keep your car in good condition by regularly changing the oil. But what type of oil should you use? This blog post will discuss the pros and cons of using 75w90 and 80w90 gear oil in your car.

80w90 vs 75w90 Table

What’s the difference between 75w90 and 80w90 gear oil? We will discuss the pros and cons of each type of oil to help you make the best decision for your needs.

Known as Mobil gear oil 75w90

Known as Gearbox 80w90

Made by Exxon Mobil

Made by Motul

100% synthetic

100% synthetic

Viscosity indexing is 144

Viscosity indexing 157

 Flash point is noted as 210°C

Flash point is noted as 198°C

Pour point is -45°C

Pour point is -24°C

The product is good to go in any season

Good for low temperatures.

This oil is a perfect fit for load carrying and heavy vehicles.

Suitable for Motorcycles and cars.

IT meets the GL-5 requirements but leaves out the GL-4

Yes. Also applicable to GL-4

This gear oil is one of the best there is and with multiple benefits, it is often enlisted in the purchase list.

This product does all the basics efficiently with the help of sturdy mineral fluids. They are valued for their quality.

Why Compare?

Gear oil protects gears from wear and tear. Gear oil is available in different weights. Different weights are for different applications. The 75W-90 gear oil is for heavy-duty use in Extreme conditions. This oil is recommended for limited-slip differential (LSD) and colder climates. The high temperatures will not bother this oil because it leaves a heavy film behind.

Gear oil 80W-90 can be used in extreme pressure conditions and as a lubricant for non-synchronized manual transmissions in heavy-duty vehicles. This gear oil is recommended for conventional and limited-slip differentials.

The main difference between 75w90 and 80w90 Gear Oil is the viscosity. The 80w90 Gear Oil is thicker than 75w90 as it has a higher viscosity index. Both oils have approximately the same flash point, fire point, and pour point temperatures. They both are safe to use with limited-slip differentials, open differentials, and manual transmissions in heavy-duty vehicles.

Both oils are suitable for cold or hot weather use and offer protection against rust, corrosion, and wear in extreme conditions. They can handle intense pressure and are ideal for heavy-duty applications.

75w90 Gear oil

Gear Oil 75w90 is an entirely synthetic gear lubricant formulated from synthetic base oils and a complicated additive system. It is designed to be used in lots of railway gearboxes and presents fantastic load-sporting functionality in which severe pressures and surprise loading are expected.

This tool’s oil presents fantastic thermal and oxidation stability, excessive Viscosity Index (VI), extraordinarily low pour point, and low-temperature fluidity. Mobil Synthetic Gear Oil 75w90 meets the API GL-five overall performance level.


  • Extraordinary thermal stability and resistance to high-temperature oxidation.
  • Outstanding protection against low speed, high torque wear, and high-speed scoring.
  • Enhanced frictional properties.
  • Low-temperature fluidity versus mineral oils.
  • Good resistance to foaming.
  • Maintains film strength for reliable lubrication.
  • Minimal deposits make sure extended gear and bearing life.
  • Longer seal life.
  • Increased load-carrying capability.
  • Significant contribution and assurance to reduced maintenance costs and longer equipment life.

80w90 Gear Oil

Mobilube HD 80W-ninety are excessive overall performance, heavy obligation tools lubricants formulated from excessive general performance base oils, and a complicated additive system. These lubricants are engineered for automobile programs, including heavy obligation axles and very last drives wherein severe pressures and surprise loading are expected. They are advocated via means of ExxonMobil for programs wherein API GL-five provider is required.


  • Thermal stability.
  • Resistant to high-temperature oxidation.
  • Firm protection against low-speed or high torque wear and high-speed scoring.
  • Excellent rust and corrosion protection.
  • Effective low-temperature lubrication.
  • Compatible with typical automotive seals and gaskets.
  • Minimal deposits ensure extended gear and bearing life.
  • Increased load-carrying capability.
  • Minimum leakage and reduced contamination.
  • Improved stability.
  • Reduced maintenance costs and longer equipment life.

What does 75w90 mean?

75w90 is a gear oil that is fully synthetic and equipped with a modern additive system. This oil is designed for heavy usage and contributes to superb oxidation and thermal stability. Fluidity at very low temperature and a level five viscosity index. 75W denotes that the oils have fluidity at -40°C, and the W is in short for winter. 90 on the last is the viscosity of the oil.

Can I use 75w90 instead of 75w85?

Yes, you can. There won’t be any noticeable difference between the two as long as they are entirely synthetic. That being said, thicker oils are better for the gears. With the 90 viscosity, you may enjoy better availability and improved cushioning.

What’s thicker 75w90 or 75w140?

While both the oils are of the same thickness at room temperature, the latter is definitely the thicker in the application. Having a glance at their names clears the confusion too. The 75w140 is known as a multi-viscosity oil that comes with the ability to preserve viscosity at soaring temperatures.

Where Is Gear Oil Used?

Although gearbox oils are mainly used in automobile gearboxes, these oils are designed to be used almost wherever gearboxes are installed. Of course, they require multiple properties because different gear materials and conditions can be challenging to use.

Determine which oil is best for each application, especially according to the different environments in which they are used. Gears generate a lot of heat and friction when they work. This means lubricating oil must be used to avoid wear between gears; otherwise, it may cause system performance degradation.

What Are Extreme Pressure Gear Oils?

EP gear oil can withstand heat and pressure far more than any other type of gear oil. Of course, this means adding a lot of additives, which can be dangerous if you are not careful about the type of machine you are using. Most of these reagents are based on chlorine or sulfur, which may be hazardous for certain metals.

For example, brass gears commonly used in worm gears soften their surface when pressed against the brass gears. It can be used at the request of the manufacturer. Other anti-wear additives, such as B. zinc-based protective agents, are suitable for applications where metals that are susceptible to corrosion by chlorine or sulfur are present.

Is It Better Synthetic Gear Oil Than Conventional Gear Oil?

Yes, synthetic oil is much better for an engine than regular oil. Although conventional oil or mineral oil can provide sufficient lubricating properties, it cannot compete with the performance and traditional protection of engines provided by synthetic oils. Compared with the less refined base oils used in ordinary oils, these are the reasons for their lagging effectiveness:

  • Poor chemical stability.
  • More susceptible to oxidation and acidification.
  • Can be destroyed more quickly.
  • Lose their protective properties easily.

Our Observation

We have observed that fully synthetic gear oils, such as 75w90, provide superior protection against wear and tear, as well as better stability and longevity. In addition, these oils are better equipped to handle extreme temperatures and conditions. Overall, we believe that synthetic gear oils are the superior choice for gearbox lubrication.

Frequently Asked Questions (FAQ)

Well, it really depends on your individual needs and preferences. If you’re looking for a gear oil that will provide superior protection in extreme temperatures, then 75w90 is the way to go. However, if you’re looking for an oil that will offer better fuel economy, then 80w90 is the better option. Ultimately, it’s up to you to decide which gear oil is best for your car.

You can use 80w90 for a manual transmission, but it is not the recommended gear oil for most applications. You may want to consider using a different-weight oil if you are having trouble with gears slipping or grinding.

Yes, you can use 80W-90 on a lower unit. This oil is typically used in gearboxes and differentials, but it can also be used in other applications where a high-quality lubricant is required. 80W-90 oil provides excellent protection against wear and tear, making it ideal for use in high-stress environments.

The “w” in 75w90 stands for “winter.” This designation is given to gear oils that perform well in cold weather. The first number, “75,” refers to the oil’s viscosity or thickness. The second number, “90,” indicates the oil’s high-temperature viscosity. Together, these numbers tell you that the oil will flow easily in cold weather and maintain its viscosity at high temperatures.



75w90 and 80w90 gear oils are fully synthetic and come with a modern additive system. They are designed for heavy usage and contribute to superb oxidation and thermal stability, Fluidity at shallow temperatures, and a level five viscosity index.

75w90 is thicker than 75w85, but both are entirely synthetic. 80w90 is also better for gears than conventional gear oil. EP gear oils are oils that can withstand heat and pressure far more than any other type of gear oil. While synthetic oils are better for engines than regular oil, EP gear oils are the best type of gear oil.

80w90 Gear Oil

75w90 Gear Oil

Check Price on AmazonCheck Price on Amazon

Related Article

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Scroll to Top