A clean diesel fuel filter improves the overall efficiency of your vehicle including performance and mileage. By changing your filter you are helping to keep the fuel pump working efficiently by removing contaminants from the system and ensuring your vehicle starts and runs smoothly at all times.
The filter is designed to trap impurities in the fuel. If the filter is not changed with regular maintenance services those impurities will enter into the fuel injectors and other fuel system components damaging them and causing costly engine repairs.