The key specifications of automotive lubricants involve multiple aspects, and the selection of these specifications is crucial to ensure the normal operation of the engine and extend its service life. The following is a detailed analysis of the key specifications of automotive lubricants:
Viscosity grade
Viscosity grade is one of the most important specifications of lubricants, which reflects the fluidity of lubricants. SAE (Society of Automotive Engineers) has developed a viscosity grade system to identify the viscosity range of lubricants at different temperatures.
1. Single-grade lubricants
It has a fixed viscosity range at a specific temperature and is mainly suitable for environments with small temperature changes or specific application scenarios. For example, SAE 40 lubricant is a single-grade lubricant, which means that the lubricant has a large viscosity range at high temperatures and is usually used to cope with high temperature and high load conditions.
2. Multi-grade lubricants
Multi-grade lubricants can maintain a relatively stable viscosity range at different temperatures. They use specially formulated additives and base oils to provide suitable lubrication performance under both low and high temperature conditions. The viscosity grade of multi-grade lubricants consists of two numbers, such as SAE 5W-30 and SAE 10W-40. The "W" stands for winter, the first number indicates the viscosity grade under low temperature conditions, and the second number indicates the viscosity grade under high temperature conditions.
When choosing lubricants, you should choose the appropriate viscosity grade according to the climate conditions and seasonal changes in the area, as well as the age, mileage and driving conditions of the vehicle.
Quality grade
The quality grade reflects the comprehensive performance of the lubricant, including anti-oxidation, anti-corrosion, clean dispersibility, etc. API (American Petroleum Institute) has formulated the quality grade standard for lubricants, which are divided into gasoline engine oil (S series) and diesel engine oil (C series).
1. Gasoline engine oil
Common quality grades include SG, SJ, SL, SM, SN, etc. Among them, SN grade is the latest API automotive engine oil performance specification, providing higher lubrication protection and better engine cleaning performance.
2. Diesel engine oil
Common quality grades include CF-4, CH-4, CI-4, CJ-4, etc. These grades correspond to different engine technologies and usage conditions.
When choosing lubricants, you should choose lubricants that meet or exceed the recommended quality grade according to the engine manufacturer's recommendations and the vehicle's usage conditions.
Other key specifications
In addition to viscosity grade and quality grade, automotive lubricants also need to consider the following key specifications:
1. Antioxidant stability
Good lubricants can effectively resist oxidation during use and reduce harmful substances produced by oxidation, thereby maintaining the cleanliness and stable performance of the lubricant.
2. Antiwear and extreme pressure
Antiwear refers to the ability of the effective lubricating film formed on the friction surface of the lubricant under light and medium load conditions to resist wear; extreme pressure refers to the ability of the lubricant to resist sintering and scratching on the friction surface under low speed and high load or high speed impact load conditions. These properties are essential for protecting the internal parts of the engine from wear and damage.
3. Detergent dispersibility
The lubricant needs to have the ability to inhibit the formation of deposits such as carbon deposits, lacquer films and sludge inside the engine to keep the engine clean and stable.
The key specifications of automotive lubricants include viscosity grade, quality grade, antioxidant stability, antiwear and extreme pressure, and detergent dispersibility. When selecting lubricants, these specifications should be considered in combination with the recommendations of the automobile manufacturer and the conditions of use of the vehicle to ensure that the engine is optimally lubricated and protected.