WARNING
Should the tire pressure drop repeatedly:
• check the tire for foreign bodies.
• check whether the wheel is losing air or the valve is leaking.
• make sure that only a valve cap approved by Mercedes-Benz is used on the tire valve.
Tire pressures that are too low have a negative effect on vehicle safety, which could lead you to cause an accident.

To test tire pressure, use a suitable tire pressure gauge. The outer appearance of a tire does not permit any reliable conclusion about the tire pressure. On vehicles equipped with the electronic tire pressure monitoring system, the tire pressure can be checked using the on-board computer.

The tire temperature and pressure increase when the vehicle is in motion. This is dependent on the driving speed and the load.

Therefore, you should only correct tire pressures when the tires are cold.

The tires are cold:
• if the vehicle has been parked without direct sunlight on the tires for at least three hours and
• if the vehicle has not been driven more than 1 mile (1.6 km).

The tire temperature changes depending on the outside temperature, the vehicle speed and the tire load. If the tire temperature changes by 18 °F (10 °C ), the tire pressure changes by approximately 10 kPa (0.1 bar/ 1.5 psi). Take this into account when checking the pressure of warm tires and only correct the tire pressure if it is too low for the current operating conditions. If you check the tire pressure when the tires are warm, the resulting value will be higher than if the tires were cold. This is normal. Do not reduce the tire pressure to the value specified for cold tires. The tire pressure would otherwise be too low.

Observe the recommended tire pressures for cold tires
• on the Tire and Loading Information placard on the B-pillar on the driver's side,
• in the tire pressure table on the inside of the fuel filler flap,
• printed in yellow on the rim of the emergency/collapsible spare wheel (depending on vehicle equipment).