2004 Mercedes CLK-Class Owner's Manual - Page 279

Operation At the gas station Warning! G i Only use premium unleaded gasoline with a minimum Posted Octane Rating of 91 (average of 96 RON/86 MON). Information on gasoline quality can normally be found on the fuel pump. More information on gasoline can be found in the Factory Approved Service Products pamphlet. i Leaving the engine running and the fuel cap open can cause the ? lamp to illuminate. More information can be found in the "Practical hints" section ( page 308). Overfilling of the fuel tank may create pressure in the system which could cause a gas discharge. This could cause the gas to spray back out when removing the fuel pump nozzle, which could cause personal injury. Replace the fuel cap by turning it to the right. You will hear when the fuel cap is tightened. Close the fuel filler flap. 279