Top 5 Best 75w140 synthetic Gear Oil in 2023

Are you looking for the best 75w140 synthetic gear oil for your heavy-duty vehicle? If you have a heavy-duty vehicle like a truck that takes high loads or a high-speed car, you should get the ideal gear oil for the gearbox. For gearboxes that run at high temperatures, 75w140 gear oil is excellent in reducing friction as well as damage.

This type of formula is beneficial for vehicles operating in challenging conditions and under high transmission workloads. This type of lubricant also offers excellent protection and enhances the overall lifespan of the gear. It also helps to reduce mechanical abrasion during operation.

This article is going to be very helpful for you since I’m going to discuss the best synthetic 75w140 gear oil. I’ll also give you some tips for choosing the 75w-140 gear oil. So, continue browsing this article and get the best synthetic gear lubricant today!

5 Best 75w140 synthetic Gear Oil in 2023


Product Name

Best For

Liquid Volume


Valvoline SynPower SAE 75W-140 Gear Oil

Valvoline SynPower SAE 75W-140 Gear Oil

Overall Best Gear Oil

1 Quarts

Lucas Oil Synthetic SAE 75W-140 Gear Oil

Lucas Oil Synthetic SAE 75W-140 Gear Oil

Best Budget Gear Oil

1-4 Quarts

Liqui Moly 75W-140 Limited Slip Gear Oil

Liqui Moly 75W-140 Limited Slip Gear Oil

Best For High-Speed Vehicles

1 Liter

Red Line 57915 75W140 GL-5 Gear Oil

Red Line 57915 75W140 GL-5 Gear Oil

Best for Lightweight Vehicles

1-20 Quarts

Royal Purple Max Gear 75W140 Gear Oil

Royal Purple Max Gear 75W140 Gear Oil

Best Quality Gear Oil

1-20 Quarts

This is the list of my top 5 picks of the best 75w140 synthetic gear Oil in 2023. Now let’s explore the comprehensive details of all these 5 formulas.

Valvoline SynPower SAE 75W-140 Gear Oil

Valvoline SynPower SAE 75W-140 is the very first product on this list of the Best 75w140 synthetic gear oil. This formula has been produced only from synthetic oils to ensure continuous and secure gear functioning. It is a top-notch formula that can keep your automobile on the road as well as perform at its best.

This Valvoline SynPower resists corrosion as well as rust and protects the gear teeth by reducing chattering. It is a premium-grade formula that is proven to enhance the overall lifespan of the gear. Moreover, this formula has been specially designed for cars and it is suitable to operate heavy loads.

YES! You can use this Valvoline SynPower oil in a truck that operates under heavy loads. The lubricant gives hypoid gear superior protection to help them employ precise mechanisms to be capable of withstanding heavy loads. Although it has been manufactured for low temperatures, the appropriate oil viscosity is sustained even under extreme temp.

However, it is made for a range of automobiles, from big buses to tiny passenger cars. Additionally, Valvoline SynPower has unique ingredients that help to lessen chattering. Overall, this oil provides a broad spectrum of efficacy to keep your car operating at its best on the road.


  • Provide excellent gear protection even at heavy load
  • Prevents corrosion and oxidation and reduces wear
  • Ensures excellent fluid protection at low-temperature
  • Appropriate for conventional and limited differentials


  • SynPower Gear Oil comes with only 1 QT package

Why buy this oil?

Valvoline SynPower SAE 75W-140 is an excellent oil that has been designed for trucks, passenger cars, and also buses. This formula ensures excellent protection for gear and performs well at any temperature. It eliminates wear and enhances gear lifespan.

Lucas Oil Synthetic SAE 75W-140 Gear Oil

It is a fantastic alternative to consider if you want gear oil made for heavy-duty vehicles and high-performance circumstances. It has excellent characteristics, which makes it entirely compatible with modern engines. It is made to be a long-lasting, non-foaming formula for trucks and other heavy vehicles when regular gear oil is insufficient.

This synthetic gear oil’s unique quality is its ability to keep lubricity even when exposed to incredibly high temperatures. This synthetic gear lubricant is extremely slick and allows for very little friction. Consequently, transmission deterioration is decreased, resulting in a longer gearbox life.

This is also a result of Lucas Synthetic Gear Oil’s ability to operate at a lower temperature and, as a result, function admirably in hot temperatures. It can withstand high temperatures with ease and maintain its viscosity. Additionally, compared to conventional lubricants, Lucas offers reduced gear noise as well as a longer bearing life.

This Synthetic Gear Oil has a unique additive package that prolongs bearing life and improves lubricity. As a result, this lubricant can shield your engine from harm and improve operation in general. Overall, using this premium quality formula in restricted slip differentials is perfect.


  • Reduce gear noise as well as enhance the bearing lifespan
  • Offers excellent protection against oxidation and corrosion
  • Excellent for heavy-duty cars as well as limited differentials
  • Ensures excellent performance at any temperature condition


  • This Lucas Synthetic Oil contains harmful chemicals in it

Why buy this oil?

Lucas Oil Synthetic Gear Oil offers complete protection for gear. It also has a long-lasting feature means you won’t have to be changed frequently. The viscosity of the substance remains constant over the broad temperature spectrum. Overall, it is an excellent choice for large cars and trucks.

Liqui Moly 75W-140 Limited Slip Gear Oil

Liqui Moly 75W-140 Limited Slip Gear Oil is a premium synthetic base formula that has been manufactured from high-quality synthetic oil and additive. It is an ideal gear lubricant solution for high-speed vehicles like motorsports cars. Liqui Moly performs admirably and is superior to all other types of gear oils.

The oil supports the gear’s trouble-free operation and considerably increases gear life. Because the oil is entirely synthetic, it will minimize oxidation and also corrosion processes as much as possible. Regardless of the surrounding temperature, it keeps the right viscosity and guarantees effective gear functioning under heavy loads.

It is made to offer axles that are under a lot of stress a break. Since this formula has remarkable lubricity, you can use it on BMW as well as other high-end vehicles to provide smooth gear changing. It guarantees perfect aggregate performance even in the most challenging circumstances and with significant temperature swings.

The lengthy gear service life of Liqui Moly eliminates the need for frequent replacements. It is excellent at lowering friction, almost eradicates rust and corrosion and is very effective at minimizing excessive wear. This oil maintains consistent viscosity and assures the gear teeth’ safety, enhancing performance and lowering energy consumption.


  • It provides superior protection for gear and also friction
  • Heavy duty formula minimizes interior gear temperature
  • It provides gentle gear shifting and extends bearing life
  • Perfect for heavy-duty motorsports and high-load trucks


  • This formula is not compatible with specific vehicles

Why buy this oil?

This Liqui Moly lubricant is highly suitable for super-fast cars and truck that takes high-load. It offers excellent protection against friction and enhances gear life. It guarantees perfect aggregate operation even in the most challenging situations and amid significant temperature variations.

Red Line 57915 75W140 GL-5 Gear Oil

Red Line 57915 75W140 is one of the most versatile synthetic oil available on the market. It is a  popular oil, especially for cars and some lightweight tracks. Most people choose the red line for their vehicles for true quality and performance. This formula has the ability to provide high protection, which makes it more efficient than other branded oil.

This oil is extremely lightweight with added friction modifier which ensures sustainability along with clutch-type slip differentials. This limited differential confirms that no additional is needed in this case. This oil contains lubrication and a perfect efficiency for operating at lower temperatures. Not only that, it has an extreme level of viscosity index. Additionally, it can exceed API GL-5 specifications with an improved formula.

Compared to other synthetic gear oil, this best 75w140 synthetic gear oil has advanced shear stability and oxidation-reducing capability. Furthermore, it has higher protection quality with longer drain intervals. An additional slipperiness that is caused by a fictional modifier is mainly responsible for the lower temperature in hypoid gears.

Its unique formulation makes impressive vehicle improvements. So, for those who are looking for a branded, long-lasting oil, this formula is an ideal choice. Overall, you can use this oil to improve your vehicle’s performance.


  • It offers excellent shear stability and exceptional gear performance
  • Offers additional lubrication at relatively any temperatures condition
  • Provide exceptional gear protection and also reduced oxidation
  • This oil offers superior performance in extreme temperature condition


  • This Red Line formula’s performance at low temp is not satisfying

Why buy this oil?

This Red Line formula works admirably in large cars that frequently have high temperatures. Under all circumstances, it significantly lowers gear wear and ensures optimum gear grip while preserving viscosity. It also offers excellent gear protection to enhance gear lifespan.

Royal Purple Max Gear 75W140 Gear Oil

Royal Purple Max 75W140 is the last product on this list of the Best 75w140 synthetic gear oil. This one is one of the popular synthetic gear oils on the market and is compatible with most cars. It has been manufactured especially for trucks and automobiles and can excellently enhance the lifespan of gear and bearings.

Max Gear features Royal Purple’s Synerlec proprietary technology, a lubricant additive innovation that thickens the oil layer for increased performance and safety. Additionally, it includes synthetic processed-based oils of the highest grade. In essence, with all of these features, this formula excellently reduces engine wear and deposits.

This gear oil prolongs the life of vehicle gears and contributes to performance softening. It includes friction modifier additives means you don’t have to use additional additives. Furthermore, it offers better corrosion protection than rival traditional and also synthetic gear oils. Without revamps, Max Gear helps gears run more quietly, quieter, cooler, and longer without revamps.

Because of its unique formulation, vehicle performance will enhance amazingly. This formula also supports higher loads as well as decreased oxidation. It is intended to deliver excellent performance in all climates. You will drive with excellent performance while using less gasoline. Overall, your vehicle will have an impressive performance after using this oil.


  • Maximize horsepower and minimize operating temperature
  • Offers corrosion protection and enhances bearing, and gear life
  • Helps the gear to run smoother, cooler, quieter, and also longer
  • Excellently reduces wear, tear, and foaming as well as oxidation


  • It is relatively sticky, which will make shifting challenging

Why Buy this Oil?

Royal Purple Max Gear 75W140 Gear Oil is an excellent lubricant for vehicles from trucks to heavy-duty cars. It is a high-performing formula that offers excellent protection and enhances the lifespan of the gear. You can be certain that the gear in your vehicle is taken excellent care of with this formula.

How to Choose the Best Gear Oil: Buying Guide

When you are going to purchase gear oil for your vehicle, there are several things to consider to choose the best formula. I’ll go over some of the significant factors you have to consider before selecting the ideal oil. So, let’s explore it.

Consider the viscosity

In order to achieve the necessary film thickness among contacting surfaces at a specific speed and load, a gear oil’s viscosity is largely determined. Finding the recommended viscosity grade in a product’s maintenance manual is typically all that is required to make the right choice. It is crucial to comprehend the selection criteria for viscosity as well as the variables influencing the need.

Highly viscous oils may require more force to operate the gears while also producing heat from inner fluid friction. Lower viscous oils can pass through the filtering system with less difficulty. Effective contamination removal lowers the chance of gear and bearing damage and lengthens the equipment’s lifespan.

Explore the Additives

Oil additives’ primary purpose is to enhance the base stock’s qualities under various operating situations and to meet the high-performance demands of any machinery. Active compounds, known as lubricant additives must mix effectively with a base oil in order for the mixture to work as a single fluid.

Manufacturers of additives frequently provide several additives for sale in additive packages that have been mixed with base oils to a greater concentration. The additive shields gear teeth against rust and corrosion, as well as chattering in limited-slip distinctions. So, explore the additives feature before buying gear oil.

Vehicle Type

The type of vehicle you wish to put synthetic gear oil in is another important thing to consider. The type of automobile is important since it can be pointless to purchase a 75w140 gear oil if it is incompatible with your vehicle.

As I discussed before, 75w140 gear oil is appropriate for trucks, luxury automobiles, heavy-duty vehicles, sports cars, and other vehicles. So, all you have to do is know the type of your vehicle, explore gear oil compatibility and then choose the best 75w140 synthetic gear oil.

Explore protective features

You should also consider the protective feature of the formula you are going to purchase. Basically, synthetic gear oil comes with several protective features, including rust, corrosion, wear, and so on. The more protective feature a formula comes with, the more it can ensure the lifespan of the gear.


Why use Synthetic Gear Oil?

Synthetic Gear Oil is made to resist extreme temps and guard against wear and strain on your gears. Additionally, it has excellent anti-foaming qualities that will protect your gears from foaming up. By preventing corrosion, it can also assist in increasing the lifespan of your gearbox.

How Often to Change Gear Oil?

You should change the gearbox oil frequently if you want to maintain your car in peak condition. Most automobiles may travel up to 80,000 miles under typical driving conditions before requiring a change. However, you should change the gear oil every 50,000 to 60,000 miles.

Is 75w140 better than 75w90?

75W-90 is the easiest to use for the front differential and works best since it ensures reduced total vehicle pressure. 75W-140 is employed in more extreme weather conditions in addition to high weights. When heavy-towing or running cars at a high rate of speed, 75W-140 is ideal for the rear differential.

Read more articles on Gear Oil

Does synthetic gear oil last longer?

Compared to mineral oils, synthetic oils are more durable and better able to withstand high temperatures. The oil change frequencies at the same ambient temperature might be 3 to 5 times longer based on the base oil.

Wrap Up

In conclusion, this article may help you get the best 75w140 synthetic gear oil for your vehicle. All of the highlighted gear oils worked admirably and offered excellent gear protection. However, when you purchase synthetic gear oil for your engine, you should know the engine type and the specs. This is because you should ensure that the gear oil is compatible with your car’s engine.

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