2006 Mercedes SL-Class Owner's Manual - Page 271

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. For more information on gasoline, see "Premium unleaded gasoline" ( page 448) or the Factory Approved Service Pamphlet. i Leaving the engine running and the fuel cap open can cause the engine malfunction indicator lamp ú (USA only) or the engine malfunction indicator lamp ± (Canada only) to illuminate. For more information, see the "Practical hints" section ( page 335). 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 clockwise until it audibly engages. Close the fuel filler flap. You should hear the latch close shut. 270