What are the main factors for selecting automotive lubricants? What does the fluidity of lubricants represent?

The lubricating oil of the car is the lubricating oil of the engine, which can keep the engine in normal working condition, which is often called motor oil. Generally, synthetic motor oil is better, and the other one should be selected according to the specific situation.

What are the main criteria for selecting automotive lubricants?

Engine lubricating oil, also called motor oil, has the functions of lubrication, cooling, cleaning, sealing, rust prevention and vibration reduction. Due to its large usage, harsh working conditions, many specifications and high performance requirements, the selection of lubricating oil is very important.

First, choose the appropriate specifications.

The ones starting with S represent lubricating oil for gasoline engines, and the ones starting with C represent lubricating oil for diesel engines. When both letters are present, it is a universal type for gasoline and diesel engines.

Common specifications include SA, SB, SC, SD, SE, SF, SG...SN

This ascending relationship of letters means that the later the letter specification, the more additives used to protect the engine and the higher the quality grade.

Secondly, the choice of engine oil should be determined according to the condition of the engine.

The newer the car, the more stringent the working conditions of the engine oil are. It is better to use a higher grade engine oil. That is, the more stringent the working conditions are, the higher the grade of the engine oil should be.

Third, the choice of engine oil in winter should be based on the temperature in different regions.

Because the viscosity of the engine oil is too high at low temperatures, it is easy to cause the oil to solidify. When the engine is started, the poor fluidity of the oil will cause dry friction of the bearing, resulting in burning of the bearing and seizure of the shaft.

Common brands include Kunlun, Great Wall, Shell, Mobil, Castrol, etc.

What does lubricant fluidity mean?

Fluidity index, namely XW-Y. XW stands for low temperature fluidity, W stands for winter, which is directly related to the cold car starting performance. The smaller the value of X, the better the low temperature fluidity, and the lower the temperature can be used. Winter oil brands are generally 0W, 5W, 10W, 15W, 20W, and 25W.

0W is an engine oil with very good low-temperature fluidity and is suitable for use in cold areas at minus 35 degrees Celsius. Therefore, 5W or 10W can be used in most areas of my country and most of the time. 0W is a waste of money and is not conducive to cold car lubrication and increases wear.

-Y represents the viscosity of the oil at 100°, which is closer to the lubrication effect under normal and stable operating conditions of the car. The larger the viscosity, the better the protection of mechanical wear, but the worse the fluidity, the higher the fuel consumption. German cars have large power reserves and good engine fuel saving effects. Appropriate use of -30 or -40 is conducive to improving engine durability, reducing oil consumption, and making the engine sound richer. At least the famous second-generation EA888 engine is suitable for this.

Will bad lubricating oil cause cylinder pulling?

1. The deterioration of engine oil causes the engine oil to lose its lubricating function.

The increase in oil in Honda is due to the fact that the vehicle is in a very cold environment and driving a short distance, which causes the temperature of the oil to rise rapidly. In addition, the direct injection engine causes the gasoline to be sprayed on the cylinder wall and then hung into the oil pan by the piston. As the temperature drops, it is difficult for the gasoline in the oil to evaporate from the oil, resulting in an increase in oil. If this increased oil is used for a long time, it may cause the engine to pull the cylinder.

2. There is a leak in the air filter or intake system.

When the engine takes in air, the dust and impurities in the air will first be filtered through the air filter, so that the clean air can enter the engine cylinder to participate in the combustion. Otherwise, the unfiltered air mixed with dust and impurities will enter the cylinder to participate in the combustion. Since dust is not flammable, these impurities will stick to the oil on the cylinder wall, and finally enter the oil pan as the piston reciprocates in the cylinder, causing the oil quality to deteriorate. The movement of the piston will also cause the cylinder to pull.