Function of the fuel filter is to filter out dusty from fuel filter. If the filter is too dirty or clogged, it will happen as follows: when the gas is added, the power is slow, or cannot get up, the car is difficult to start, sometimes it takes 2 to 5 times to hit the fire.
Most engines are equipped with good quality filters. The replacement cycle is generally 10,000 kilometers. If you add gasoline with less impurities, it is not a problem to replace one at 15,000 to 20,000 kilometers. The filter has arrow marks on the inlet and outlet ports, so do not install it backwards when replacing it.