2003 Mercedes E-Class Owner's Manual - Page 270

Operation Tires and wheels Tire 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 pressure where the temperature is different from the outside temperature. Tire temperature and tire pressure are also increased while driving, depending on the driving speed and the tire load. Check the spare tire periodically for condition and inflation. Spare tires will age and become worn over time even if never used, and thus should be inspected and replaced when necessary. Warning! Do not overload the tires by exceeding the specified vehicle capacity weight (as indicated by the label on the pillar in the driver's door opening). Overloading the tires can overheat them, possibly causing a blowout. i Possible differences between the readings of a tire pressure gauge of an air hose, e.g. gas station equipment, and the vehicle's control system can occur. The readings issued by the control system are more precise. Switch on ignition. Press the k button until the current inflation pressures for each tire appear in the multifunction display. Checking tire pressure electronically* The tire inflation pressure monitor only functions on wheels that are equipped with the proper electronic sensors. It monitors the tire inflation pressure, as selected by the driver, in all four tires. A warning is issued to alert you to a decrease in pressure in one or more of the tires. Tire pressure inquiries are made using the multifunction display ( page 121).The present inflation pressures are displayed only after a few minutes' travel time. You can select the unit of measurement used for the tire inflation pressure by changing the setting in the control system ( page 136). G Do not overinflate tires. Overinflating tires can result in sudden deflation (blowout) because they are more likely to become punctured or damaged by road debris, potholes etc. Follow recommended inflation pressures. 270