The filter is generally better to be replaced once every 5000 kilometers: 
1. Cars must be maintained regularly, and the oil and oil filters, air filters, fuel filters, etc. need to be replaced during maintenance, referred to as "three filters";
2. Everyone can understand that when changing the oil, any oil has a shelf life, and the quality of the expired oil decreases, which reduces the protection of the engine;
3. The oil filter is called the "kidney of the engine". Its main function is to filter impurities in the oil and provide clean oil to the engine. During the operation of the engine, a large amount of carbon deposits, gums, sludge, metal wear debris, etc. will be generated. If these impurities are not filtered out, it will aggravate the wear of the engine;
4. The air filter is called "the mask of the engine", its function is to filter out the sand, impurities, etc. in the air, and provide clean air to the engine. If the air enters the engine directly without filtering, the hard particles such as sand particles and impurities in the air will enter between the piston and the cylinder wall, which will aggravate the wear of the cylinder and shorten the service life of the engine;
5. Fuel is the "food" of the engine. Fuel is divided into gasoline and diesel. Their filters are slightly different. Today we only talk about gasoline filters. The function of the gasoline filter is to filter impurities, gums, etc. in the gasoline, provide clean gasoline to the engine, and prevent "disease from entering the mouth". Fuel is inevitably mixed with some impurities during production and transportation, and some moisture will be adsorbed during storage. These impurities will seriously damage the components in the fuel system. For example, the extremely precise fuel injector coupler has an accuracy of only a few microns. If impurities and gums in gasoline enter the coupler, the surface of the coupler will be scratched, which will cause the injector to drip and fail to open.