Contents
- Editor’s Choice
- Rating of the top 10 best gear oils according to KP
- How to choose gear oil
- Popular questions and answers
Gear oil is necessary to lubricate metal parts and bearings, as well as to prevent their grinding during movement and, accordingly, wear. In both automatic and manual transmissions, it provides hydraulic pressure and friction so that internal parts can perform their function correctly.
Oils have different compositions and properties, as each transmission has different lubrication requirements. For this reason, liquids are divided into different classes:
- mineral;
- synthetic;
- semi-synthetic.
Mineral oils are natural lubricants containing a mixture of hydrocarbons. They are a product of the oil refining process.
They have a low viscosity index: at extremely high temperatures they become thinner and give a thinner lubricating film. These oils are the most affordable.
Synthetic oils are artificial liquids that have been purified and broken down using chemical equipment. Because of this, they are more expensive, but the benefits justify the expense. This oil has good thermal stability before high temperatures: it accumulates less sludge, carbon or acids. Thus, its service life is increased.
And the absence of wax means the oil is suitable for use at extremely low temperatures.
Semi-synthetic oil A high performance heavy duty automotive transmission fluid. This is the golden mean – the oil is of better quality than mineral oil and will cost less than synthetic. It delivers higher performance levels than pure natural oils and also bonds well with them, making it suitable as a drain or fill replacement.
Together with an expert, we have prepared a ranking of the best gear oils on the market in 2022.
Editor’s Choice
LIQUI MOLY fully synthetic gear oil 75W-90
It is a synthetic gear oil for mechanical, auxiliary and hypoid transmissions. Promotes quick engagement of friction clutches, lubrication of gears and synchronizers. Good protection against rust, corrosion, wear. It has an extended service life – up to 180 thousand km.
The high-performance fluid is based on base oils and modern additive components. This enables a wide range of applications with optimum gear lubrication, especially under extreme operating conditions. Meets API GL-5 classification requirements.
Main characteristics
| Composition | synthetic |
| Gearbox | mechanical |
| Viscosity | 75W-90 |
| API standard | GL 5 |
| Shelf life | 1800 days |
Advantages and disadvantages
Rating of the top 10 best gear oils according to KP
1. Castrol Syntrans Multivehicle
Low-viscosity synthetic gear oil that provides economy in all-weather operation. It fully complies with the requirements of API GL-4 classification and can be successfully used in all passenger car transmissions with relevant requirements, including gearboxes. Low foaming keeps lubrication effective at high speeds.
Main characteristics
| Composition | synthetic |
| Gearbox | mechanical |
| Viscosity | 75W-90 |
| API standard | GL 4 |
| Shelf life | 5 years |
Advantages and disadvantages
2. Motul GEAR 300 75W-90
Synthetic oil is suitable for most mechanical transmissions where API GL-4 lubricants are required.
Minimum change in oil viscosity with changes in ambient and operating temperatures.
Main characteristics
| Composition | synthetic |
| Gearbox | mechanical |
| Viscosity | 75W-90 |
| API standard | GL-4/5 |
| Shelf life | 5 years |
Advantages and disadvantages
3. MOBILE Mobilube 1 SHC
Synthetic transmission fluid formulated from advanced base oils and the latest additive system. Formulated for heavy-duty manual transmissions that require gear lubricants with high load carrying capacity over a wide temperature range and where extreme pressures and shock loads are expected.
Main characteristics
| Composition | synthetic |
| Gearbox | mechanical |
| Viscosity | 75W-90 |
| API standard | GL-4/5 |
| Shelf life | 5 years |
Advantages and disadvantages
4. Castrol Transmax Dell III
SAE 80W-90 semi-synthetic multi-purpose oil for manual transmissions and final drives. Recommended for heavily loaded passenger cars and truck differentials where API GL-5 performance is required.
Main characteristics
| Composition | semi-synthetic |
| Gearbox | Automatic |
| Viscosity | 80W-90 |
| API standard | GL 5 |
| Shelf life | 5 years |
Advantages and disadvantages
5. LUKOIL TM-5 75W-90
Oil for mechanical transmissions with any type of gears, including hypoid ones, for cars, trucks and other mobile equipment. The fluid is produced using refined mineral and modern synthetic base oils in combination with an effective additive package.
Main characteristics
| Composition | semi-synthetic |
| Gearbox | mechanical |
| Viscosity | 75W-90 |
| API standard | GL 5 |
| Shelf life | 36 months |
Advantages and disadvantages
6. Shell Spirax S4 75W-90
Premium quality semi-synthetic automotive gear lubricant specially formulated for use in transmissions and axles. Advanced base oil technology provides superior shear stability. Minimal change in viscosity with changes in operating and ambient temperatures.
Main characteristics
| Composition | semi-synthetic |
| Gearbox | Automatic |
| Viscosity | 75W-90 |
| API standard | GL 4 |
| Shelf life | 5 years |
Advantages and disadvantages
7. LIQUI MOLY Hypoid 75W-90
Semi-synthetic gear oil provides high-quality friction of parts in the gearbox and their resistance to aging. Even in the most difficult conditions and with large temperature fluctuations, it guarantees uninterrupted operation of the car. Good lubrication reliability, maximum wear protection due to wide viscosity range.
Main characteristics
| Composition | semi-synthetic |
| Gearbox | mechanical |
| Viscosity | 75W-90 |
| API standard | GL-4/5 |
| Shelf life | 1800 days |
Advantages and disadvantages
8. Gazpromneft GL-4 75W-90
The transmission fluid is made from quality base oils for heavy duty applications where special protection against wear and scuffing is required. Most suitable for trucks.
Main characteristics
| Composition | semi-synthetic |
| Gearbox | mechanical |
| Viscosity | 75W-90 |
| API standard | GL 4 |
| Shelf life | 5 years |
Advantages and disadvantages
9. OILRIGHT TAD-17 TM-5-18
Universal all-weather oil designed for off-road vehicles. Developed for both manual and automatic transmissions of various manufacturers. Meets API GL-5 requirements.
Main characteristics
| Composition | Mineral |
| Gearbox | Mechanical, automatic |
| Viscosity | 80W-90 |
| API standard | GL 5 |
| Shelf life | 1800 days |
Advantages and disadvantages
10. Gazpromneft GL-5 80W-90
Gear oil designed for use in transmission units subject to high loads (final gear, drive axles). The oil effectively protects the parts of hypoid gears from wear and scuffing.
Main characteristics
| Composition | Mineral |
| Gearbox | mechanical |
| Viscosity | 80W-90 |
| API standard | GL 5 |
| Shelf life | 5 years |
Advantages and disadvantages
How to choose gear oil
To choose the right oil for you, you need to assess the operating conditions of the car, know the type of gearbox. Guided by this information, you can safely proceed to the choice of transmission fluid. Pay attention to two important characteristics: the viscosity index of the oil and the API classification.
Classification of gear oils
Gear oils have a base grade that defines most of their qualities. At the moment, most of them are outdated for use and only GL-4 and GL-5 grade gear oils are used in modern cars. API classification provides for division mainly by the level of extreme pressure properties. The higher the GL group number, the more effective the additives that provide these properties.
| GL 1 | This class of gear oils is designed to work in simple conditions without special loads. For agricultural machinery and trucks. |
| GL 2 | Standard products designed for mechanical transmissions operating under moderate conditions. It differs from GL-1 oils in better anti-wear characteristics. Used for the same vehicles. |
| GL 3 | These oils are used in manual transmissions where the qualities of a GL-1 or GL-2 oil would not be sufficient, but they do not require the load that a GL-4 oil can handle. They are typically used for manual transmissions that operate in moderate to severe conditions. |
| GL 4 | Designed for transmission units with all standard types of gears that operate under medium and heavy loads. It is used in modern passenger cars of various types. |
| GL 5 | Oils are used in harsh operating conditions, contain many multifunctional additives with phosphorus sulfur elements in the base. Used for the same vehicles as the GL-4 |
Gear oils can also be classified according to viscosity index. Below is a table of specific characteristics and applications:
| Index | Index decryption |
| 60, 70, 80 | Oils with this index are summer. They are suitable for the southern regions of Our Country. |
| 70W, 75W, 80W | Winter are designated by such an index. They are recommended for use in the north of the Federation, in areas with low temperatures. |
| 70W-80, 75W-140, 85W-140 | All-weather oils have a dual index. Such liquids are universal, they are recommended for use in the central part of the country. |
Popular questions and answers
Answered popular questions about gear oils Fedorov Alexander, senior master of car service and auto parts store Avtotelo.rf: