Fuel filter used in car removes any impurities (rust and dust particles) so as to ensure decreased wear and tear of the engine components and fuel pump. A fuel filter is made of either plastic and metal with a filter paper fitted inside. It is located in between the fuel tank and the fuel pump. The fuel filter gets clogged if not replaced at regular intervals and eventually will decrease the fuel supply to the engine. A clogged fuel filter can be found responsible when there is a decrease in fuel efficiency or when the car takes longer to start. Sometimes, the car stops running at all due to no flow of fuel to the engine. So replacing the filter time to time will improve the performance of the engine and fuel efficiency because of lesser contamination, though there are a few fuel filters that can be removed, cleaned and replaced in the same location afterwards. As per Car experts fuel filter must be changed for every 20,000km and an inexpensive way to increase the longevity of engine.