Mercedes-Benz Mercedes CLK 2002-2009 Fuel System Specifications

The 2002-2009 Mercedes CLK models are designed to run on premium unleaded gasoline with an octane rating of 91 or higher. Using lower-octane fuel may result in reduced performance and engine knocking. Diesel variants are not available for this model range. Always refer to the owner's manual for specific fuel recommendations and compatibility details.

The fuel system in the 2002-2009 Mercedes CLK requires regular maintenance, including fuel filter replacement every 30,000 to 40,000 miles. Inspect fuel lines for leaks or wear annually. Use fuel system cleaners periodically to prevent injector clogging. Adhering to the manufacturer's maintenance schedule ensures optimal performance and longevity of the fuel system.

To replace the fuel filter, first, relieve fuel system pressure by removing the fuel pump fuse and running the engine until it stalls. Locate the fuel filter, typically under the car near the fuel tank. Disconnect the fuel lines and remove the old filter. Install the new filter, ensuring proper orientation, and reconnect the fuel lines. Restore fuel system pressure and check for leaks.

Poor fuel efficiency in the 2002-2009 Mercedes CLK can result from clogged fuel injectors, a dirty air filter, or improper tire pressure. Start by checking and replacing the air filter if necessary. Use a fuel injector cleaner and ensure tires are inflated to the recommended pressure. If issues persist, inspect the oxygen sensors and fuel system for faults.

To optimize fuel performance, use premium unleaded gasoline and maintain a regular maintenance schedule. Keep the air filter clean, ensure proper tire inflation, and avoid excessive idling. Use fuel system cleaners periodically and drive smoothly to reduce fuel consumption. Regularly inspect and replace worn components like spark plugs and oxygen sensors.