Technical features of oil filter:

1. Filter paper: The oil filter has higher requirements on the filter paper than the air filter, mainly because the temperature of the oil varies from 0 to 300 degrees. Under the severe temperature change, the concentration of the oil also changes accordingly. This affects the filtered flow of oil. The filter paper of the high-quality oil filter can filter impurities and ensure sufficient flow under severe temperature changes.

2. Rubber sealing ring: The filter sealing ring of high-quality oil is made of special rubber to ensure oil-free leakage.
Backflow Suppression Valve: Available only in premium oil filters. When the engine is turned off, it prevents the oil filter from drying out; when the engine is re-ignited, it immediately creates pressure to supply oil to lubricate the engine.

3. Relief valve: only available in high-quality oil filters. When the outside temperature drops to a certain value or when the oil filter exceeds its normal service life, the overflow valve opens under special pressure, allowing unfiltered oil to flow directly into the engine. Nonetheless, impurities in the oil will enter the engine, but it is much smaller than the loss caused by no oil in the engine. Therefore, the relief valve is the key to protect the engine in an emergency.