There are built-in and external gasoline filter elements. Roewe i5 gasoline filter is located in the fuel tank. As the name implies, its main function is to filter impurities in gasoline. At present, there are two main types of gasoline filter elements in cars. The first type is external, generally installed under the automobile chassis near the fuel tank, with oil inlet and oil outlet at both ends and a circular filter element in the middle, but there are also some models with three interfaces. This extra interface is used to control the gasoline pressure. If the pressure is higher than the standard value, gasoline will flow back to the fuel tank from this connection. The external gasoline filter elements are basically similar in appearance, some may be longer and some may be thicker, but they are all similar.