Replacement Cycle of Automotive Air Filters

An air filter is like the "mask" of an engine, designed to prevent large particles from being sucked into the engine along with the air. Studies show that if the air entering the engine contains particles with a diameter larger than 20 microns, it is highly likely to cause abnormal wear to the engine. The air filter cartridge is installed at the front end of the engine's intake system to trap dust and impurities in the incoming air, preventing larger particles from entering the engine interior.

You can easily locate the air filter element by opening the engine compartment. Replacing it yourself is straightforward—just unscrew the bolts and open the cover. Most ordinary family cars use dry paper air filter cartridges, which have a mesh structure inside and can filter out particles larger than 5 microns. However, over time, the accumulated trapped particles and dust will clog the filter's mesh. This blockage hinders the engine's normal air intake, leading to insufficient air supply and reduced engine power.

To maintain the power output required by the driver, the engine's Electronic Control Unit (ECU) will increase fuel injection, raising the concentration of the air-fuel mixture in the engine. Simply put, it trades higher fuel consumption for more power, which in turn causes increased fuel usage. Additionally, paper filters may become moldy over time and are prone to being sucked apart by the engine's intake force. After all, the engine's pistons move back and forth like a syringe. If the filter is torn, the impurities and particles trapped on it will definitely be sucked into the engine cylinders, resulting in engine wear.

For these reasons, air cartridge filters need to be replaced regularly. However, there is no universal standard for the "regular" replacement interval, as the content of impurities and particles in the air varies across different regions. In northern and northwestern regions of China such as Gansu and Xinjiang, where the air contains relatively high levels of dust, the air element filter may need to be replaced every 5,000 to 8,000 kilometers. In contrast, in southern regions with less industrial activity, the air contains almost no industrial dust, so the filter can last longer—10,000 to 20,000 kilometers is completely feasible. Therefore, the replacement cycle should be determined based on the dust levels in the area where the car is frequently driven: shorter intervals for dustier areas and longer intervals for areas with less dust.