What is the difference between 75W90 and 80W90 gear oil?
The main difference between 75W90 and 80W90 gear oils lies in their viscosity and performance characteristics. Both are common types of gear lubricants used in various automotive and industrial applications, but they have distinct properties that make them suitable for different use cases.
Viscosity Differences
The numbers in the gear oil designations refer to the oil's viscosity, which is a measure of its thickness or resistance to flow. The "W" stands for "winter" and indicates the oil's low-temperature viscosity, while the second number represents the oil's high-temperature viscosity.
75W90 gear oil has a lower viscosity at low temperatures (75W) and a higher viscosity at high temperatures (90) compared to 80W90 gear oil. This means that 75W90 oil is thinner and flows more easily in cold conditions, making it better suited for use in colder climates or during winter months. Conversely, 80W90 oil is slightly thicker and more viscous, providing better protection in warmer operating conditions.
Performance Characteristics
The viscosity differences between 75W90 and 80W90 gear oils also affect their performance characteristics:
- 75W90 gear oil is generally better suited for applications that require improved low-temperature fluidity, such as in differentials, manual transmissions, and transfer cases in cold weather regions. It can help improve fuel efficiency and reduce wear on components during cold starts.
- 80W90 gear oil is more suitable for use in warmer climates or applications that experience higher operating temperatures, such as heavy-duty commercial vehicles, industrial gear boxes, and off-road equipment. It provides better high-temperature viscosity and shear stability, helping to maintain a protective lubricating film under high-stress conditions.
It's important to consult the manufacturer's recommendations for the specific equipment or vehicle to determine the most appropriate gear oil viscosity for the application and operating conditions.
What is 80w90 gear oil used for?
The 80W-90 gear oil can be used in extreme pressure conditions and as a lubricant for some non-synchronized manual transmissions in heavy-duty trucks or buses.
What is the temperature range for 75W90 gear oil?
300°F to + 350°F. Excellent seal compatibility and increased seal life.
Which is better, 75W80 or 75W90?
At 75W90 the kinematic viscosity is 13.5 to 18.4 mm²/s. 75W90 offers better shear stability than 75W80 and can generally withstand higher loads in the transmission. Oils of different SAE classes can be mixed with each other.
Is thicker diff oil better?
Using thicker oil:
Better acceleration. Increases on-power steering (reduces understeer) Better suited on high-bite, smooth tracks. Too thick oil gives more over steer.
What's thicker than 75W90?
So, the difference between "75W90" and "75W140" is that at operating temperature, the 75W140 will be considerably thicker than the 75W90 but at room temperature they will be about the same viscosity.
What is 75w-90 used for?
Product Description. Mobil Synthetic Gear Oil 75W-90 is a fully synthetic gear lubricant formulated from synthetic base oils and an advanced additive system. It is designed for use in many railway gearboxes and provides excellent load-carrying capability where extreme pressures and shock loading are expected.
Is 75W90 the same as 10W40?
75W90 corresponds to 10W40 motor oil in absolute viscosity. That's why a common mistake is to think a transmission fluid is thicker (has a higher viscosity) than it actually is. One more API classification for gear oils is MT-1.
Can I use 75W90 gear oil instead of 80w90?
75W-90 is fine. The only difference between 75W-90 and 80W-90 is the cold flow characteristic, 75W will flow faster. Both are 90 wt at operating temperature. You can use Severe Gear 75W-90 in the front, I do. Or you can save a few $$ and use this since the front axle sees less use.
Which grade gear oil is best?
The American Petroleum Institute (API) has established standards for gear oil performance. Look for the API classification on the product label, such as API GL-4 or API GL-5. The API GL-4 is suitable for lower torque, synchromesh transmissions, while API GL-5 is designed for higher torque, hypoid gear systems.
Is 80W thicker than 75W?
SAE 75W-90 maintains a more consistent thickness, or viscosity, across a wide temperature range. It's thicker when exposed to high heat and thinner under colder, wintry conditions than 80W-90. The use of 75W-90 gear oil is recognized by OEMs as a contributor to overall fuel economy.
