Fuel Filter
Its function is to filter out harmful particles and water in the fuel gas system of the engine to protect the oil pump nozzle, cylinder liner, piston ring, etc., reduce wear and avoid blockage. Filter out the iron oxide contained in the fuel.
Even if the diesel has been precipitated and filtered before being added to the diesel fuel tank, it is clean, but during the fueling process, the diesel will still be polluted due to factors such as fueling tools, fueling environment, and unclean fuel tank ports. The impurities deposited in the fuel system and the suspended particles in the air will also pollute the diesel oil, so the diesel filter on the car is essential, not to mention that the diesel oil is not necessarily really clean before it is added to the fuel tank.