2008 Mercedes SL-Class Owner's Manual - Page 304

Operation Tires and wheels i If you have overfilled the tire, release tire inflation pressure by pushing the metal stem of the valve with e.g. a tip of a pen. Then recheck the tire inflation pressure with the tire gauge. Install the valve cap. Repeat this procedure for each tire. Run Flat Indicator (Canada only) While the vehicle is being driven, the Run Flat Indicator monitors the set tire inflation pressures by evaluating each wheel's rotational speed. This allows the system to detect a significant loss of pressure in a tire. If a wheel's rotational speed changes due to falling tire inflation pressure, you will see a corresponding warning message in the multifunction display. The Run Flat Indicator may function in a restricted manner or with a delay if snow chains are mounted to the vehicle in presence of ice and snow if you are driving on a loose surface (e.g. sand or gravel) if you are driving in a very sporty manner (involving rapid acceleration or high speeds in curves) Warning! G When the multifunction display shows the message Tire Pressure Check Tires, one or more of your tires is significantly underinflated. You should stop and check your tires as soon as possible, and inflate them to the proper tire inflation pressure as indicated on the vehicle's Tire and Loading Information placard or, if available, on the tire inflation pressure label. Driving on a significantly under-inflated tire causes the tire to overheat and can lead to tire failure. Underinflation also reduces fuel efficiency and tire tread life, and may affect the vehicle's handling and stopping ability. Each tire, including the spare, should be checked monthly when cold and set to the recommended tire inflation pressure as specified on the Tire and Loading Information placard on the driver's door B-pillar ( page 295) or, if available, on the tire inflation pressure label located on the inside of the fuel filler flap ( page 279). 303