The quality of the oil filter is very important to the car. The oil filter element is the oil filter. The function of the oil filter is to filter out debris, colloids and moisture in the oil, and to deliver clean oil to each lubricating part. In order to reduce the frictional resistance between the relative moving parts in the engine and reduce the wear of the parts, the oil is continuously delivered to the friction surface of each moving part to form a lubricating oil film for lubrication.

Technical characteristics of oil filter:
1. Filter paper: Oil filters have higher requirements for filter paper than air filters, mainly because the temperature of the oil varies from 0 to 300 degrees. Under severe temperature changes, the concentration of the oil will also change accordingly, which will affect the filtering flow of the oil. The filter paper of a high-quality oil filter must be able to filter impurities under severe temperature changes while ensuring sufficient flow;
2. Rubber sealing ring: The filter sealing ring of high-quality engine oil is made of special rubber to ensure 100% oil leakage;
3. Backflow suppression valve: only available in high-quality oil filters. When the engine is turned off, it can prevent the oil filter from drying out; when the engine is re-ignited, it immediately generates pressure to supply oil to lubricate the engine. Also called a check valve;
4. Relief valve: only available in high-quality oil filters. When the external temperature drops to a certain value or when the oil filter exceeds the normal service life, the overflow valve will open under special pressure, allowing unfiltered oil to flow directly into the engine. The overflow valve is the key to protect the engine in an emergency, also known as the bypass valve.