Contaminants can plug fuel injectors or carburettors, causing engine malfunction and deterioration. Dirt, rust, scale and water are the major impurities present in fuel. These impurities can originate from dirty and rusty service station storage tanks and, as the vehicle ages, from corrosion within the fuel system components. Therefore, they must be removed from the fuel to avoid damage or malfunctions in the various components of the fuel system.