Contaminants in engine fuel can clog the drilled or cored passages in carburetor, upsetting their metering performance, causing loss of power, poor engine starting, damaged exhaust valves etc. Dirt, rust, scales and water are the major impurities present in fuel. Replacing your vehicle's filters on a regularly scheduled basis will help the vehicle run better and last longer. ACDelco fuel filters are designed to remove all the contaminants from fuel. All the fuel must pass through the filter before it goes to fuel injection system. Clean filters contribute to better fuel economy and reduced vehicle operating costs.