2007 Mercedes CLS-Class Owner's Manual - Page 303

Operation Tires and wheels Important notes on tire inflation pressure Warning! i Driving comfort may be reduced when the Checking tire inflation pressure Regularly check your tire inflation pressure at least once a month. Check and adjust the tire inflation pressure when the tires are cold. The tires can be considered cold if the vehicle has been parked for at least 3 hours or driven less than 1 mile (1.6 km). If you check the tire inflation pressure when the tires are warm (the vehicle has been driven for several miles or sitting less than 3 hours), the reading will be approximately 4 psi (0.3 bar) higher than the cold reading. This is normal. Do not let air out to match the specified cold tire inflation pressure. Otherwise, the tire will be underinflated. G tire inflation pressure is adjusted to the value for speeds above 100 mph (160 km/h) as specified on the placard located on the inside of the fuel filler flap. If the tire inflation pressure repeatedly drops: Check the tires for punctures from foreign objects. Check to see whether air is leaking from the valves or from around the rim. Be sure to readjust the tire inflation pressure for normal driving speeds. You should wait until the tires are cold before adjusting the tire inflation pressure. Some vehicles may have supplemental tire inflation pressure information for vehicle loads less than the maximum loaded vehicle condition. If such information is provided, it can be found on the placard located on the inside of the fuel filler flap. Tire inflation pressure changes by approximately 1.5 psi (0.1 bar) per 18°F (10°C) of air temperature change. Keep this in mind when checking tire inflation pressure where the temperature is different from the outside temperature. Tire temperature and tire inflation pressure are also increased while driving, depending on the driving speed and the tire load. If you will be driving your vehicle at high speeds of 100 mph (160 km/h) or higher, where it is legal and conditions allow, consult the placard on the inside of the fuel filler flap on how to adjust the cold tire inflation pressure. If you do not adjust the tire inflation pressure, excessive heat can build up and result in sudden tire failure. 302