Composition of oil filter:
1. Filter paper
Oil filters have higher requirements for filter paper than air filters. The filter paper of high-quality oil filters needs to filter impurities smoothly and ensure sufficient flow rate under changes in oil temperature.
Cheap filter paper is often made of cotton pulp paper, which has poor filtering effect and is easy to decompose and dissolve into the engine oil, blocking the oil passage, accelerating the deterioration of the engine oil, and causing engine damage.

2. Rubber sealing ring
The high-quality oil filter sealing ring is made of special rubber synthesis, ensuring 100% oil leakage.
A good oil filter will not leak oil under normal installation conditions. The problem of cheap oil filters leaking oil is severe.

3. Backflow suppression valve
Only available in high-quality oil filters. When the engine shuts down, it can prevent the oil filter from drying out; When the engine is ignited again, it immediately generates pressure and supplies oil to lubricate the engine.
The cheap oil filter does not have a check valve, which accelerates the wear and tear of the engine during starting.

4. Bypass valve
Only available in high-quality oil filters. When the oil filter exceeds its normal service life, the overflow valve will open under special pressure to ensure that the engine has sufficient oil supply. Regularly replace the oil filter to avoid engine wear.
The cheap oil filter does not have a bypass valve, and in special cases, there is no lubricating oil supply, resulting in the engine being scrapped.