Find the best solution for your gear and transmission 

You ought to provide extensive lubrication to some of the critical parts of your engine to maintain the optimum functioning of your vehicle. The gearbox and the transmission need ample lubrication for their smooth functioning. This is because these parts include components that engage in immense metal to metal contact. 

We have brought you the best 75w90 synthetic gear oil for this purpose. Our selected oils are meant to boost the longevity of your engine and serve the best of its qualities. When the functioning of these areas is smoothened, the overall performance of your engine is bound to benefit.

The best 75W90 synthetic gear oil 

	Product	Oil type	Viscosity	Size	Check Today’s Price
1.	Mobil 1 75W-90 Synthetic Gear Oil	Fully synthetic	75W-90	4 Quart	Click Here
2.	Lucas Oil 10047 Synthetic Transmission and Differential Gear Oil	Fully synthetic	75W-90	1 Quart	Click Here
3.	Red Line MT-90 75W-90 Gear Oil	Fully synthetic	75W-90	1 Quart	Click Here
4.	Valvoline SynPower SAE 75W-90 Gear Oil	Fully synthetic	75W-90	4 Quart	Click Here
5.	Castrol 06674-6PK Syntrax Limited Slip 75W-90 Gear Oil	Fully synthetic	75W-90	1 Quart	Click Here
6.	Royal Purple 01300 Max Gear 75W-90 Gear Oil	Fully synthetic	75W-90	1 Quart	Click Here

1. Mobil 1 75W-90 Synthetic Gear Oil 

This exceptional gear oil ensures the best performance while limiting the slip and friction in the critical components of your engine. Unlike other options, this fully synthetic gear oil does not contain any wax. 

This gear oil contains certain unique friction modifiers that work well for limited-slip differentials. You do not have to employ any additional limited-slip chemicals for this purpose. However, it is recommended that you utilize an additional sulfur-phosphorus additive for improved overall functionality. 

The thermal stability of this gear oil is very high. It avails excellent protection to your engine from wear and tear. It also protects your engine from oxidation and limits corrosion. In humid environments, it protects the engine from forming rust. 

This gear oil is also known for its exceptional shear stability. So the viscosity of this oil will remain unchanged even if the pressure rises. Overall, the performance of your engine will be rendered superb. You’ll see a certain improvement in the torque, power output, and acceleration of your engine.

Pros 

• This gear oil is well regarded for its limited-slip action 
• It certainly reduces the friction between the moving parts of the engine 
• The engine is protected from corrosion and from the formation of rust 
• The fuel mileage is improved 
• The thermal and shear stability of this gear oil is also very high 
• You’ll see definite improvements in the torque and the power output 
• You don’t need any additional anti-slip additives along with this gear oil 

Cons 

• The packaging of this gear oil is inadequate 

Verdict 

This gear oil is meant to enhance the performance of your engine and improve the limited-slip action.

2. Lucas Oil 10047 Synthetic Transmission and Differential Gear Oil

This specialized non-foaming gear oil is meant to provide the best in class performance. Lucas gear oil is known to avail the most extensive lubrication and reduce the metal-to-metal friction between the moving parts of your engine. This oil is widely recommended for limited-slip differentials. 

This oil is highly suggested for use in heavy-duty vehicles because of its prolonged action and slick nature. This oil is specially designed to avail the most extensive lubrication to your gears and bring out the utmost smooth functionality of your engine. 

The lubricating action of this engine oil is functional even when the temperature and pressure conditions are extreme. The viscosity of this gear oil remains unchanged when the conditions are challenging. This is owed to the immense thermal and shear stability of this gear oil. Moreover, this gear oil is quite affordable as compared to other contenders. 

Pros 

• This is a very economical gear oil 
• It has a non-foaming nature
• This gear oil has a prolonged action 
• It is most suitable for heavy-duty vehicles
• This gear oil enhances the performance of the engine 
• It avails extensive lubrication 
• The functionality of your engine is rendered smooth 
• This gear oil has a high thermal and shear stability 
• This oil is quite economical 

Cons 

• Users report issues with quality 

Verdict 

This affordable gear oil is highly recommended for use in heavy-duty vehicles owing to its prolonged action. 

3. Red Line MT-90 75W-90 Gear Oil

If you are looking for the gear oil with the maximum thermal stability, this is the one. Red Line MT-90 gear oil is especially suitable for manual transmission. It avails an easy, fast, and smooth shift and is utilized by the most reputable brands in their cars. 

This gear oil ensures the most optimum protection for your gears and benefits the overall performance of your engine. You’ll see great improvements in your torque and horsepower. Even the acceleration of your engine will be benefited. 

The sulfur content of this gear oil is far low as compared to most other oils. This is how it is safe for your engine. The viscosity of this gear oil remains stable even when the temperature and pressure conditions are extreme. The amazing thermal and shear stability makes this oil very reliable as it does not break down in the face of challenges.

The engine also stays protected from damage by deteriorating agents. Moreover, it is equipped with a special technology that reduces slippage. It works admirably well for both low mileage and high mileage vehicles at all sorts of temperatures.

Pros 

• This gear oil has amazing thermal and shear stability 
• It is highly recommended for manual transmission systems 
• The performance of your engine is enhanced 
• This oil works well for both low and high mileage vehicles 
• This gear oil is very versatile 
• It provides the best shifting response 
• The coefficient of friction is improved
• This oil will improve your engine’s torque and horsepower 

Cons 

• This gear oil is more expensive than the others

Verdict 

This gear oil provides the most smooth shifting and can alter the coefficient of friction. It is widely utilized for the most prominent cars.

4. Valvoline SynPower SAE 75W-90 Gear Oil 

This fully synthetic gear oil is meant to serve you for a long time. Coming from a reputable brand, this high-quality gear oil is equipped with unique additives that enhance its action. These additives help in ensuring the cleanliness of the engine and in preventing the development of rust and corrosion. 

This oil provides extensive lubrication even when the temperature conditions are extreme. The thermal stability is high and the viscosity remains stable under challenging temperature and pressure conditions. Moreover, this gear oil is believed to perform much better when the pressure is high. 

It is highly suggested for non-synchronized manual transmission systems. The fuel economy and the performance of your engine are enhanced.

Pros 

• This gear oil has excellent thermal stability 
• It renders a prolonged action period 
• There are unique additives that prevent corrosion 
• The fuel economy is enhanced 
• The performance of your engine is boosted
• The functionality of your engine is smoothened
• The engine is protected from corrosion 

Cons 

• This gear oil can irritate the eyes

Verdict 

This gear oil provides a prolonged service life and improves the fuel economy of your engine. 

5. Castrol 06674-6PK Syntrax Limited Slip 75W-90 Gear Oil 

This exceptional gear oil has a prolonged service life and provides an extended drain interval. This oil does not need frequent changes. This fully synthetic engine oil provides ample protection and lowers the frictional coefficient. The extensive lubrication along with the reduction of the frictional coefficient works in favor of improving the functionality of the engine. 

The engine is protected from damage by corrosion and rust. Also, this oil has a high thermal and shear stability. This oil does not deteriorate when the temperature and pressure conditions become challenging. 

Moreover, this gear oil is compatible with most other synthetic and conventional engine oils. The engine is protected from wear and tear and the operation of the engine is made smooth. 

Pros 

• This gear oil has a high thermal and shear stability 
• It has a prolonged service period
• The drain intervals are extended 
• It protects the engine from wear and tear 
• The thermal and shear stability of this oil is high 
• It is compatible with most other conventional and synthetic gear oils 
• This oil provides adequate lubrication 
• It also lowers the frictional coefficient 

Cons 

• No negative reviews 

Verdict 

This gear oil is much recommended for extended drain intervals and its ability to lower the coefficient of friction. 

6. Royal Purple 01300 Max Gear 75W-90 Gear Oil

This tough gear oil is meant for heavy-duty vehicles. It is known to boost the power output and protect the engine from damaging factors. The noise created by the engine is minimized. This oil also prevents your engine from overheating.

Equipped with the unique hypoid friction modifiers, this gear oil will improve the overall performance of your engine and make its functioning smooth. It removes the corrosive elements from your engine and benefits its durability. The wear and tear of the engine are also reduced.

Moreover, this oil also extends the longevity of your bearings. Unlike most other gear oils, it is not corrosive in action upon copper, bronze, and brass. The efficiency of your engine is increased and the drag is minimized. 

Pros 

• This gear oil helps in improving the power output 
• It enhances the durability of your engine 
• It protects the engine against corrosion 
• This oils also lowers the friction coefficient and makes the operation smooth 
• The longevity of your bearings is also enhanced 
• The fuel mileage of your engine is improved 
• The power output is increased
• This oil is suggested for heavy-duty vehicles 

Cons 

• This gear oil is not suitable for Toyota vehicles 

Verdict 

This tough gear oil is meant for heavy-duty vehicles and it improves the power output of your engine.

Conclusion 

We have brought you the best 75W-90 synthetic gear oils. Now you can maintain the optimum safety of the critical parts of your engine. The wear and tear of these parts will be reduced. The use of this oil will definitely enhance the longevity of your engine. The reduction of friction between the moving parts of the engine ensures smooth functionality. 

Our selected products are certainly worth the price and most of them are quite affordable. Whether you change your vehicle’s engine oil after every six months or a year, these oils will definitely be economical. The longevity of your vehicle will surely be enhanced.

These engine oils are the best way to effectively maintain your vehicle and make good things last for a long time. You must get your hands on our selected range and experience the best your vehicle has to offer.