75w140 Vs 80w90 Gear Oil – Which One Is Right For You?

Automobiles have countless intricate differentials. These parts must be maintained regularly so that they can occasionally be confident when the vehicle is in use. Ultimately, this can help an automobile owner have a much better driving experience.

Lubricant oils play a vital role in prolonging the lifespan of automotive devices by lubricating their moving parts. 75w90 and 80w90 are among the most popular gear oil variations currently available in the market.

However, there are numerous motorists who are perplexed as to which one from 75w140 vs 80w90 to choose because of their complex specifications.

If you’re one of them as well, this article is for you. Here we’re going to compare some important factors regarding these two oil variations.

What Does It Mean by 75W140 in Gear Oil?

The “W” (W winter suitability) value indicates how well the oil flows in cold temperatures. 75W transmission fluid remains flowable down to 40 degrees Celsius. The kinematic viscosity of transmission fluid at 100 degrees Celsius is designated as the number “140”. It has a viscosity range of 24.0 and 32.4 BMWs.

What Does It Mean by 80W90 in Gear Oil?

The 80–90 choice gives you two viscosity numbers relating to viscosity. One number is the viscosity as oil freezes in a cooler environment and the other one is the viscosity in warmer times. The ‘W’ standing for Winter Stability means an improved viscosity at colder temperatures. The second number, which is 90, signifies the needed thickness at 100C.

75w140 Vs 80w90 Gear Oil – Head to Head Comparison

Different oils are designed for different types of engines and can make a big difference in how your car runs. Here, we will be comparing the 75w140 vs 80w90 gear oils, head to head. Both oils have their own benefits and drawbacks, so it is important to choose the right one for your vehicle.

Viscosity Level

Differentials in viscosity level between gear oils can affect the performance of a vehicle. Gear oil viscosity levels are specified in terms of weight-volumetric oil flow (WVOF), which is the measure of how much fluid can be pumped per minute through a restriction diametrical to the orifice plate.

The viscosity of the 75w140 gear oil is high enough to allow it to withstand extreme heat and cold. The high level of viscosity protects the oil from poor performance across a range of demanding temperatures.

A derivative of mineral oil, 80W-90 gear oil is utilized in machinery that needs oil at temperatures that are very low.

The lower the viscosity level of the fluid, the less vigorous the motion of its parts will become at extreme temperature and pressure levels. The oil becomes thinner at extremely high temperatures to accelerate the deterioration of components.

For this, 75W140 gear oil is the optimal choice for axle operating at high temperatures owing to its high productivity, dependability, and durability.

Additive Properties

75w140 motor oil incorporates a set of friction-reducing additives that stop oiled parts from wearing out prematurely. These additives also improve the sturdiness of the shared axle, making it tape-friendly in three different temperature ranges.

80W90 motor oil contains special anti-wear and lubricating additives that protect against vehicle depreciation in particularly challenging applications. These additives have heat-resistant properties as well. So, in terms of additive properties, both 75w140 and 80w90 gear oils are notably good.

density of the Oil

The density of 75W140 gear oil is 0.89. It indicates that the lubricant is thicker to afford protection against wear and abrasion at high temperatures. But with high density, the oil becomes clumpy and reduces the working efficiency of drive systems at low temperatures.

Whilst, the incandescent density of 80 W90 gear oil is 0.90. The gear oil is light but can nevertheless protect against gears in critical environments. The thin oil maintains a high level of performance even in harsh conditions with low maintenance costs.

This subcategory’s winner is 75w140, given its higher density rating than that of 80w90. The thickness enables certain applications to withstand much higher temperatures.

75w140 vs 80w90 – Which is Better? – Final Opinion

In the case of 75w140 oil, its viscosity level is higher than that of 80w90 oil. Higher viscosity gear oils can tolerate higher temperatures than lower viscosity gear oils. 75w90 oil has maximum protection for gears against wear.

However, 75w-90 gear oil becomes thicker in colder temperatures and negatively affects the performance of gears. The most suitable option under these circumstances is 80w90 gear oil.

The anti-seize solution can effectively resist extreme temperatures including frigid and arid conditions. At the present time, 75w-90 and 80w-90 gear oils are the most active. They protect the machine from premature damage. But 80w90 gear oil is less efficient when mechanically involved with high temperature.

Some Common Frequently Asked Questions


Can you use 80w90 instead of 75w140?

Yes, but only when you have synthetic 75w140 gear oil.

What is the kinematic viscosity of 75w-110 and 80w-90?

Kinematic viscosity @ 40 degrees Celsius (ASTM D445) for 80W-90 is approximately 120, while for 75W-140 is approximately 177. For 75W-110 is approximately 140.

Can I use 75w140 instead of 80w90?

Either a single type is adequate. Generally, the synthetic 75w-140 gear oil is for HD applications like towing, however, it is fine in any application.

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