Transmission Oils: Best 75W-140 Synthetic Gear Oil

Transmission oil provides low friction of internal gears and their safety during operation. Depending on the type of transmission and loads, the appropriate lubricant is used. Best 75W-140 synthetic gear oils are useful at high transmission loads and vehicle operation in harsh conditions. 75W-140 oil is suitable for winters and retains its properties at -40F, which is indicated by the number 75. This oil is universal, which means that it can work equally well in any season, providing the necessary protection even at extreme loads and temperatures inside the system due to friction of mechanical elements.

In general, all 75W-140 oils are synthetic and protect the transmission from overheating and wear. During operation, mechanical parts of the transmission are exposed to severe mechanical abrasion. To reduce it and ensure effective waste residue outflow, frictional synthetic oil with high viscosity is used.

Viscosity is the most important indicator in the operation of vehicle transmissions, which are exposed to increased loads. In this review, you can find the most universal and high-quality oils by proven manufacturers, which have long proven themselves on the market, providing high-quality service materials for various vehicles.

These oils are supplied in different volumes, but it should be said that you need to change the oil 75W-140 much less frequently compared to other oils. This means that even a small volume should be enough for a long period.

List of Top-Rated Best 75W-140 Synthetic Gear Oil

Ford Genuine Fluid XY-75W140-QL SAE 75W-140Ford Genuine Fluid
XY-75W140-QL SAE 75W-140
Synthetic Rear
Axle Lubricant
Valvoline SynPower SAE 75W-140Valvoline SynPower
SAE 75W-140
Full Synthetic Gear Oil
Royal Purple ROY01301 MAX GEAR 75W140Royal Purple ROY01301
High Synthetic Gear Oil
Amsoil Severe Gear SAE 75W140Amsoil Severe Gear
SAE 75W140
Synthetic Gear Lube
Mobil 1 102490 75W-140Mobil 1 102490 75W-140Synthetic Gear Lube
Red Line 57915 75W140 GL-5Red Line 57915
75W140 GL-5
Gear Oil
Lucas 10122 75/140Lucas 10122 75/140Synthetic Gear Oil

Reviews of the Best 75W-140 Synthetic Gear Oil

Ford Genuine Fluid XY-75W140-QL SAE 75W-140 Synthetic Rear Axle Lubricant – 1 Quart – Pack of 4

Ford Genuine Fluid XY-75W140-QL SAE 75W-140 Synthetic Rear Axle Lubricant - 1 Quart - Pack of 4

Motorcraft SAE 75W-140 Synthetic Rear Axle Lubricant is designed by Ford and meets all the standards and requirements of the company. Basically, it’s a mixture of synthetic oils, which provide the most enhanced wear protection of hypoid gears during their friction. In addition to reducing operating temperatures, the oil also removes all friction residues and prevents/eliminates all signs of rust and corrosion.

This unique lubricant is designed for continuous use and suitable for a variety of vehicles, from passenger cars to buses. The oil has a wide operating temperature range, so it’s used both in winter and summer. This is one of the most effective and stable oils of the 75W-140 series on the market. The high viscosity index of this oil allows applying it to vehicles, exposed to extreme loads. For this reason, the oil is chosen by drivers who prefer aggressive off-road driving or have to put their vehicles to considerable challenges.


  • Original Ford synthetic lubricant
  • Maintains stable axle operation at extreme loads
  • Reduces operating temperatures.
  • Keeps hypoid gears safe and prevents rust/corrosion


  • Manufacturer: Motorcraft (Ford)
  • Lowest ambient temperature: -56.2F
  • Volume: 0.95 liter
  • Weight: 7.9 lbs

Motorcraft SAE 75W-140 Synthetic Rear Axle Lubricant is the right choice for those who need a stable oil that can withstand extreme temperatures and strong mechanical stress during gear operation. The oil is supplied in branded red 1-quarter gallons. The set includes 4 gallons. The total weight of the parcel is about 7.9 lbs. If you need high-quality oil that does not need frequent changes, it’s an excellent solution to enhance your vehicle’s performance.

Valvoline SynPower SAE 75W-140
Full Synthetic Gear Oil 1 QT

Valvoline SynPower SAE 75W-140 Full Synthetic Gear Oil 1 QT

Valvoline SynPower SAE 75W-140 Full Synthetic Gear Oil is made entirely from synthetic oils, which together ensure uninterrupted and safe gear operation. It is especially relevant for vehicles that are subjected to high operating loads. The lubricant provides excellent protection for hypoid gears, which use precise mechanisms that can withstand extreme loads. The required oil viscosity is maintained even at high temperatures, although this oil is designed specifically for extremely low temperatures.

The product works perfectly during severe winter seasons and provides reliable protection for gear teeth. Valvoline SynPower prevents oxidation and corrosion. In addition, this oil reduces wear, which significantly extends its service life.


  • Provides low-temperature fluid protection
  • Prevents gear corrosion and oxidation 
  • Reduces wear of gear components
  • Provides exceptional thermal stability
  • Contains special additives for enhanced protection


  • Manufacturer: Valvoline
  • Volume: 1 quarter
  • Weight: 1.9 pounds

Valvoline SynPower SAE 75W-140 Full Synthetic Gear Oil is produced in grey gallons. One gallon has a standard volume of 1 quart. The lubricant is perfect for passenger cars, trucks, and buses. It’s designed to provide exceptional gear protection at extreme loads, sub-zero temperatures, and temperature changes. 

Royal Purple ROY01301 MAX GEAR 75W140, 1 quart

Royal Purple ROY01301 MAX GEAR 75W140, 1 quart

Royal Purple Max Gear 75W-140 High-Performance Synthetic Automotive Gear Oil is a high-quality product, designed to ensure proper operation of hypoid gears in vehicles and sea vessels. This oil provides great protection against overheating, as it’s designed to withstand extreme ambient temperatures. The oil significantly reduces friction and maintains proper homogeneous consistency, regardless of the temperature. Thus, it guarantees gentle gear shifting and significantly reduces friction.

Compared to other regular oils, Royal Purple Max Gear maintains correct gear operation in the long run. The lubricant reduces wear and reliably protects gear from rust and corrosion. The manufacturer claims that Max Gear is also beneficial in terms of fuel economy and vehicle HP.


  • Provides exceptional gear protection
  • Ensures gentle gear shifting
  • Lower coefficient of friction
  • Extends gear and bearing life


  • Manufacturer: Royal Purple
  • Volume: 1 quarter
  • Weight: 1.8 ounces

Max Gear is a great solution for pickup trucks and other sizeable vehicles, which are based on a differential with increased internal resistance. The lubricant is supplied in branded 1-quart purple gallons. Royal Purple Max Gear 75W-140 High-Performance Synthetic Automotive Gear Oil is high performance automotive hypoid gear oil that provides reliability and long service life for various marine and ground equipment.

Amsoil Severe Gear SAE 75W140

Amsoil Severe Gear SAE 75W140

Amsoil Severe Gear provides greater efficiency in comparison with other basic oils. It’s designed specifically for vehicles at constant extreme loads when towing, racing, climbing, or driving off-road. The oil significantly extends gear life and ensures its trouble-free operation at low temperatures. Amsoil Severe Gear provides 20% better performance at low temperatures and maintains proper density at high temperatures, preventing overheating of the shifting system.

The oil is fully synthetic, which allows for minimizing oxidation processes and corrosion. Amsoil Severe Gear 75W-140 provides reliable protection against premature gear wear and ensures smooth and clear gear shifting. It is specifically designed for hypoid gears and works efficiently at extreme loads.


  • Improved performance at low temperatures
  • Reliable protection against corrosion and oxidation
  • Perfect for high-load applications
  • Fully synthetic oil


  • Manufacturer: Amsoil
  • Volume: 1 quarter
  • Weight: 1.76 lb

Amsoil Severe Gear is perfect for gears that are subject to extreme loads when towing, hauling heavy loads, climbing, or off-road applications. It will also be an ideal choice for racing cars or driving in low ambient temperatures.

Mobil 1 102490 75W-140 Synthetic Gear Lube – 1 Quart

Mobil 1 102490 75W-140 Synthetic Gear Lube - 1 Quart

Mobil 1 has long established itself on the market and its production is preferred by many car enthusiasts and mechanics. Mobil 1 102490 75W-140 Synthetic Gear Lubricant is a high-quality synthetic oil that maintains proper viscosity, regardless of the ambient temperature, and ensures efficient gear operation at extreme loads.

Mobil 1 Synthetic Gear Lube doesn’t need frequent changes and provides long gear service life. It eliminates corrosion, reduces friction, and effectively removes wear products. This lubricant is recommended for proper gear operation at low temperatures (down to -49F). The oil does not lose its density and viscosity at both low and high temperatures.


  • Heavy-duty product
  • Effectively reduces interior gear temperature 
  • Maintains constant viscosity
  • Can be safely used at sub-zero temperatures
  • Comes in handy gallons


  • Manufacturer: Mobil 1
  • Volume: 1 quarter
  • Weight: 1.7 lb

This product is suitable for light pickup trucks, vans, and SUVs that are subjected to heavy loads. Mobil 1 Synthetic Gear Lube ensures that gear teeth are safe and continue to function properly. It can also be used for refueling. The oil has the right temperature properties and indicators of consistency/viscosity, which improves the overall performance of the vehicle and reduces fuel consumption.

Red Line 57915 75W140 GL-5 Gear Oil – 1 Gallon

Red Line 57915 75W140 GL-5 Gear Oil - 1 Gallon

Red Line 75W-140 High-Performance Gear Oil is a unique lubricant designed to exceed API GL-5 specifications. The oil ensures a long service life of gears and provides smooth gear shifting. The oil maintains optimal viscosity and provides proper gear grip, reducing wear. This oil is fully synthetic and has high stability and homogeneity. It can withstand low and high temperatures, which makes it suitable for both cold winters and hot summers. In fact, it’s all-seasonal oil, which doesn’t need frequent changes at ambient temperature changes.

The oil has optimal friction characteristics, reduces wear of gear elements and maintains the necessary temperature. Red Line 75W-140 High-Performance Gear Oil is designed for intensive vehicle operation and considerable fuel economy. It’s a high-quality product that extends gear service life and improves its performance. 


  • Ensures ideal gear performance
  • Maintains consistent viscosity
  • Provides superior shear stability
  • Contains additional friction modifier
  • Provides extra slipperiness to lower operating temperatures 
  • High viscosity index (VI)
  • Ensures reduced oxidation
  • Provides better fuel economy and less wear


  • Manufacturer: Lucas Oil
  • Volume: 3,8 liters
  • Weight: 7.6 pounds

Lucas Oil 75/140 is an excellent option for sizeable vehicles and trucks that need oil change. The oil provides full gear protection and does not require frequent changes. Lucas Oil 75/140 is supplied in large 3.8-liter gallons. This volume is enough for quite a long time. The oil should not be stored in a place accessible for kids and animals, dermal exposure should also be avoided.


75W-140 oils are used for heavy transmission and maintain high viscosity even at the lowest temperatures. This is a universal type of oil, which can be used in any season. At high temperatures, it’s much more efficient than 75W-90, although it has its own application peculiarities. When choosing 75W-140 oil, you need to pay attention to things like operation conditions of your vehicle, your gear type, and load intensity. Opt for proven manufacturers that guarantee the quality of their production, made from high-quality synthetic compounds.

Frequently asked question

Which oil is thicker: 75W-90 or 75W-140?

These oils have some differences in their viscosity levels. First of all, these depend on the ambient temperature. It should be noted that both oils are designed for use at temperatures down to -40F and are perfect for winters, as they will maintain the same density and viscosity at the lowest temperatures. However, if we take high temperatures (up to 104F), 75W-90 oil will become thinner and start to lose its original properties, compared to 75W-140. Thus, 75W-140 shows greater stability and remains more viscous and dense at both low and high temperatures. It’s a universal all-season type of oil, suitable for many heavy-duty trucks.

Can you use 75W-140 instead of 75W-90?

It’s worth noting that 75W-140 is used in more severe weather conditions, as well as at heavy loads. 75W-90 is simpler and is best suited for the front differential, ensuring a lower overall pressure on the vehicle. As for 75W-140 gear oil, it assumes aggressive load when towing, hauling heavy loads, and driving off-road or climbing. It’s best suited for the rear differential. This is when it makes sense to change 75W-90 to 75w140 oil. In addition, consider the temperature because 75W-140 better retains its viscosity when heated, and 75W-90 oil film becomes thinner at high temperatures of up to 40F.

What type of gear oil should I use?

Choosing the right gear oil depends on several conditions. The first thing to consider is the operating conditions, under which the oil will be used and its application area. For this purpose, gear oil has certain marks on the gallons. Pay attention to the letter designations – “W” indicates that the oil is intended for use in winter but it does not mean that you can’t use it in summer.

Neighboring numbers will determine the temperature at which the oil does not lose its viscosity and provides the necessary performance of the systems.
In addition, there is a classification of the oil application, which allows you to make the right choice for specific conditions. Thus, GL-4 oil is designed for gears used in different conditions and is suitable for both minor and heavy loads. The oil has special anti-wear additives, which ensure proper wear reduction. GL-5 class oils (75W-140 oil) are used for hypoid gears at extreme loads.

What is the best synthetic gear oil?

The best synthetic gear oil on the market is from proven and reliable manufacturers. Many people claim that more and more fake oils have recently entered the market, so knowing what the original oils are and what gallons they use, you can avoid poor-quality oil. The best original gear oils are produced by Motorcraft. These high-quality products are suitable for pickup trucks and passenger cars.

Also, Mobil 1 is the unambiguous leader on the market. This manufacturer produces synthetic oils of excellent quality. They retain their primary characteristics for as long as possible and provide long-term operation of all vehicle systems.

Red Line 75W-140 is perfectly suitable for different pickup trucks, as well. It ensures better vehicle performance, improves fuel economy, and keeps gear elements in great condition. The oil maintains viscosity at high and low temperatures, providing smooth operation of the system. Many drivers consider this oil to be the best in its class. 

Editorial Staff

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