Can I Use 80W90 Instead of 75W90: Ultimate Comparison Guide.

Published by Dustin Babich on

No, 80w90 cannot be used instead of 75w90 as they have different viscosities and performance specifications. Choosing the right gear oil is important for the longevity and performance of your vehicle’s transmission and differential.

The numbers in gear oils refer to their viscosity grade and their ability to withstand different temperatures. 75w90 and 80w90 are both gear oils commonly used in vehicles, but they have different thicknesses and lubricating properties. While it may be tempting to use 80w90 instead of 75w90 due to availability or cost, it is not recommended as it can cause damage to your vehicle’s transmission and differential.

It is best to stick to the recommended gear oil for your specific vehicle.

Understanding Gear Oil Viscosity

Gear oil viscosity refers to the thickness or fluidity of the oil at different temperatures. The viscosity of gear oil is a significant factor when it comes to protecting vital engine components from wear and tear caused by friction. It is crucial to pick the correct one for your car to maintain engine health and performance.

Viscosity is measured using standardized tests to determine the oil’s resistance to flow at different temperatures. The number before the w in gear oil viscous rating indicates the oil’s cold temperature, while the number after w represents its hot temperature.

The main differences between 75w90 and 80w90 classifications are their viscosity ratings and temperature ranges. Always use the oil viscosity recommended by the manufacturer to ensure optimal performance and prevent damage to your car.

Comparison Of 75W90 Vs. 80W90 Gear Oil

75w90 and 80w90 gear oils are similar, but have some notable differences. The main difference is their viscosity at low temperatures. 75w90 is thinner than 80w90 when cold, which makes it better suited for cold weather conditions. However, it may become too thin when exposed to very high temperatures.

On the other hand, 80w90 is thicker at low temperatures and retains its properties at high temperatures. It is better suited for warmer climates and heavy usage. Ultimately, the best choice depends on the conditions and requirements of your vehicle.

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75w90 is more fuel-efficient, while 80w90 provides better protection and durability. Both have advantages and disadvantages, so it’s important to consult with a professional and follow the manufacturer’s recommendations before making a decision.

Advantages Of Using 80W90 Gear Oil

Using 80w90 gear oil has several advantages. The first is an improved load-carrying capacity compared to 75w90. This means the oil can handle heavier workloads, making it ideal for large vehicles and machinery. Additionally, 80w90 has better resistance to aging and oxidation, meaning it lasts longer before breaking down.

Finally, it has enhanced thermal stability, meaning it can handle high temperatures for extended periods without breaking down. All of these benefits make 80w90 an excellent choice for those looking to improve their gear oil performance.

Advantages Of Using 75W90 Gear Oil

Using 75w90 gear oil can greatly improve fuel efficiency, as it greatly reduces friction and drag in the transmission. Additionally, it provides superior cold start-up performance, which is a great advantage in cold climates. This type of oil also helps reduce wear on transmission components, enhancing the overall lifespan of the transmission.

While 80w90 can be used in some situations, it lacks the same level of performance as 75w90 and is not recommended for modern transmissions. The benefits of using 75w90 gear oil far outweigh any potential drawbacks and should be the preferred choice for optimal transmission performance.

Which One To Use And When?

When deciding between 80w90 and 75w90 gear oil, certain conditions favor the use of 80w90. For example, if the temperature is high or the vehicle is subjected to heavy loads or towing, 80w90 may be the better choice. However, 75w90 is recommended for cold temperatures or when fuel economy is a concern.

In specific scenarios, expert recommendations can guide your decision. Keep in mind that using the wrong viscosity of gear oil can result in damage to your vehicle’s engine. By carefully considering the conditions in which your vehicle operates, you can choose the optimal gear oil for your needs.

Frequently Asked Questions On Can I Use 80W90 Instead Of 75W90

Can I Use 80W90 Instead Of 75W90 In My Car?

Yes, you can use 80w90 instead of 75w90 in your car as both are api gl-5 ratedand compatible.

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What Is The Difference Between 80W90 And 75W90?

The difference between 80w90 and 75w90 is the thickness of the oil at different temperatures. 75w90 is preferred in colder weather and for improved fuel economy, while 80w90 is better for higher temperatures and heavy-duty use.

Is 80W90 Thicker Than 75W90?

Yes, 80w90 is generally thicker than 75w90. The number before the “w” refers to the winter grade and indicates how well the oil flows at cold temperatures, while the number after the “w” refers to the viscosity of the oil at high temperatures.

Can Using 80W90 Instead Of 75W90 Cause Damage To My Car?

No, using 80w90 instead of 75w90 should not cause any damage to your car as long as both are api gl-5 rated and compatible with your car. However, using an oil that is not recommended for your car can cause damage to the engine.

What Type Of Cars Require 75W90 Oil?

Most modern cars require 75w90 oil for their manual transmissions and differentials. Always refer to your car owner’s manual to ensure you use the correct oil for your car.


After understanding the viscosity rating and the differences between 80w90 and 75w90, it’s clear that although they both have almost the same viscosity, they aren’t interchangeable. Using the wrong gear oil can cause damage to your vehicle’s transmission, which can lead to costly repairs.

80w90 and 75w90 hold different grades and specifications that have been designed to tackle specific temperatures and environments. A clear understanding of viscosity, performance expectations, and the manufacturer’s recommendation is crucial in selecting the right gear oil for your vehicle.

You don’t want to find yourself stranded on the road with a damaged transmission, all because you chose the wrong gear oil. By sticking to the recommended specifications or seeking professional advice, you can be confident that you are using the optimal fluid for your vehicle’s performance and longevity.

Don’t make the mistake of risking damage to your vehicle and always choose the right gear oil for your needs.

Dustin Babich
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Dustin Babich

Dustin Babich

As the passionate author behind, Dustin Babich is a knowledgeable expert in all things automotive. With a deep understanding of car tools, equipment, engines, and troubleshooting techniques, Dustin Babich shares invaluable insights, practical tips, and effective solutions to empower readers in overcoming car-related challenges.


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