2011 Mercedes SL-Class Owner's Manual - Page 181

At the gas station Mercedes-Benz Center to have the fuel system drained completely. 179 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. Please contact gas station personnel in case labels on the pump cannot be found. For more information on gasoline, see "Premium unleaded gasoline" (Y page 306), see "Fuel requirements" (Y page 307), or contact an authorized Mercedes-Benz Center, or visit www.mbusa.com (USA only). Locking/unlocking the vehicle with the SmartKey or KEYLESS-GO automatically locks/unlocks the fuel filler flap. X Turn off the engine. i Leaving the engine running and the fuel filler cap open can cause the yellow fuel tank reserve warning lamp to flash and the malfunction indicator lamp = (USA only14) or ; (Canada only14) to illuminate. For more information, see also "Practical hints" (Y page 263). X i In case the central locking system does not release the fuel filler flap, or the opening mechanism is clamping, contact Roadside Assistance or an authorized Mercedes-Benz Center. The fuel filler flap is located on the right-hand side of the vehicle towards the rear. Remove the SmartKey from the starter switch. KEYLESS-GO: Open the driver's door. This puts the starter switch in position 0, same as with the SmartKey removed from the starter switch. The driver's door then can be closed again. X Opening: Press fuel filler flap : at the point indicated by the arrow. X Turn fuel filler cap ; counterclockwise. X Take off fuel filler cap ;. X Place fuel filler cap ; in direction of arrow into holder =. X Fully insert filler nozzle unit and refuel. X Only fill your tank until the filler nozzle unit cuts out - do not top off or overfill. X Closing: Turn fuel filler cap ; clockwise until it audibly engages. X Close fuel filler flap :. 14 Depending on vehicle production date, U.S. vehicles may be equipped with the Canada engine malfunction indicator lamp ;. Z Operation ! To prevent damage to the catalytic converters, only use premium unleaded gasoline in this vehicle. Any noticeable irregularities in engine operation should be repaired promptly. Otherwise, excessive unburned fuel may reach the catalytic converter, causing it to overheat and potentially start a fire.