274 OperationTires and wheelsTire 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 also in-
crease while driving, depending on the
driving speed and the tire load.Check the spare tire periodically for condi-
tion and inflation pressure. Spare tires will
age and become worn over time even if
never used, and thus should be inspected
and replaced when necessary or after a
maximum of six years.
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 is-
sued 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 130). The in-
flation pressures are displayed only after a
few minutes travel time.
You can select the unit of measure used for
the tire inflation pressure by changing the
setting in the control system (
page 130).
iThe pressures listed for light loads are
minimum values offering high driving
comfort.
Increased inflation pressures listed for
heavier loads may also be used for light
loads. These higher pressures produce
favorable handling characteristics. The
ride of the vehicle, however, will be
somewhat harder. Never exceed the
max. values or inflate tires below the
min. values listed on the fuel filler flap.
Warning!
G
Follow recommended tire inflation pres-
sures.
Do not overinflate tires. Overinflating tires
can result in sudden deflation (blowout) be-
cause they are more likely to become punc-
tured or damaged by road debris, potholes
etc.
Do not underinflate tires. Underinflated tires
wear unevenly, adversely affect handling
and fuel economy, and are more likely to fail
from being overheated.
Do not overload the tires by exceeding the
specified vehicle capacity weight (as indicat-
ed by the label on the pillar in the driver’s
door opening). Overloading the tires can
overheat them, possibly causing a blowout.
