FAW-Volkswagen original engine oil sae5w40, what exactly is it?

SAE5W-40 refers to the original engine oil. 5W represents winter oil. Oil grades are divided into: 0W, 5W, 10W, 15W, 20W, 25W. The smaller the number before W, the higher the number. The smaller the low-temperature viscosity, the lower the applicable minimum temperature. 40 represents summer oil, and the oil grades are divided into: 20, 30, 40, and 50. The larger the number, the greater the viscosity and the higher the applicable maximum temperature.

According to API quality classification, engine oil is divided into gasoline engine series (i.e. S series) and diesel engine series (i.e. C series). The oils in each series are arranged in English alphabetical order and divided into several levels.

Extended information:

Oil selection method:

Clear appearance, low sulfur content (less than 1.0%), low residual carbon content (less than 1.0% by weight) ), less water and sediment (less than 0.1% by volume), and less ash (less than 0.03% by weight).

Common characteristics of inferior diesel on the market: turbid appearance, failure to meet the prescribed label, failure to meet the prescribed low calorific value, high sulfur content, many impurities, high moisture content, and residual carbon content high.

Hazards of using inferior diesel:

1. High sulfur content: destroys the quality of the engine oil, causes the oil to prematurely reduce its performance, and prevents the engine from being well lubricated.

2. The low calorific value cannot reach the specified value: the fuel consumption rate is higher than the calibrated engine and cannot reach the calibrated rated power.

3. High residual carbon content: Excessive carbon deposits are produced during combustion, which affects the combustion effect of the engine. The combustion chamber is too high, causing early damage to the piston, piston rings and cylinder liners. The fourth hazard of using inferior diesel:

4. High moisture content: destroys the lubrication of precision parts of the fuel pump and injector.

5. Contains a lot of impurities: Damages the precision parts of the fuel pump and fuel injector, and the wear of the fuel injector hole becomes larger.

6. The diesel separator is easily blocked, the power of the generator set is reduced, and the diesel separator replacement interval is shortened.

Reference: Baidu Encyclopedia-Motor Oil