The fuel filter is an important component in the fuel system of automobile engines. 

The following is a related introduction:

Function

• Protect the engine: filter out solid debris such as iron oxide, dust and water in the fuel to prevent it from entering the engine, 

protect the oil pump, nozzle, cylinder liner, piston ring and other components, reduce wear, avoid blockage, and ensure stable 

operation of the engine.

• Improve fuel efficiency: ensure the cleanliness of the fuel, make the fuel burn fully, improve fuel economy, reduce exhaust 

emissions, and optimize engine performance.

Classification

• According to the type of fuel: there are diesel filters, gasoline filters and natural gas filters. Diesel filters can be divided into 

diesel water separators and diesel fine filters, and gasoline filters can be divided into carburetor type and electronic injection type.

• According to the installation position: gasoline filters can be divided into in-line and built-in types. The in-line gasoline filter 

is located outside the fuel tank and is easy to replace; the built-in gasoline filter is located inside the fuel tank, with a high 

gasoline pass rate, but it is difficult to replace and has high maintenance costs.

• According to whether it is removable: it can be divided into removable and non-removable types. The removable gasoline 

filter is mainly composed of a cover, a filter element, a sedimentation cup, etc.; the non-removable gasoline filter uses a sealed 

thin shell and a special filter element.

Structure

It is generally composed of a shell, a filter element, an oil inlet, an oil outlet, a dust cover, a sealing gasket, etc. The shell is mostly 

made of aluminum or metal, and the filter element is mostly made of filter paper, but also nylon cloth, polymer materials, ceramics, etc., 

in a chrysanthemum shape to increase the flow area.

Working principle

The fuel filter is connected in series on the pipeline between the fuel pump and the oil inlet of the throttle body. After the fuel enters the filter, 

the filter element filters out impurities and water, and the clean fuel passes through the filter element into the engine fuel system.

Maintenance

The fuel filter is a consumable and needs to be replaced regularly. The specific replacement cycle varies depending on the filter type, 

vehicle usage and manufacturer recommendations. Generally, a gasoline filter needs to be replaced every 20,000 to 40,000 kilometers, 

and the diesel filter replacement cycle may be shorter.