Mercedes-Benz M-Class Owner's Manual page 363

Tyre pressure
360
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WARNING
Should the tyre pressure drop repeatedly:
check the tyre for foreign bodies.
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check whether the wheel is losing air or the
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valve is leaking.
make sure that only a valve cap approved
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by Mercedes-Benz is fitted on the tyre
valve.
Tyre pressures that are too low have a nega-
tive effect on vehicle safety, which could lead
you to cause an accident.
If possible, only correct tyre pressures when
the tyres are cold.
The tyres are cold:
if the vehicle has been parked with the tyres
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out of direct sunlight for at least three
hours and
if the vehicle has not been driven further
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than 1.6 km
Depending on the ambient temperature, the
speed you are driving at and the load on the
tyres, the tyre temperature and thus the tyre
pressure may change by approximately
10 kPa (0.1 bar/1.5 psi) per 10 †. Take this
into account when checking the pressure of
warm tyres and only correct it if it is too low
for the current operating conditions.
Driving with tyre pressure that is too high or
too low can:
shorten the service life of the tyres
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cause increased tyre damage
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have a negative effect on handling charac-
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teristics and thus the driving safety (e.g. by
causing aquaplaning)
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The tyre pressure values given for low
loads are minimum values which offer you
good ride comfort characteristics.
However, you can also use the values given
for higher loads. These are permissible and
will not adversely affect the running of the
vehicle.
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Environmental note
Check the tyre pressure regularly, at least
every 14 days.
You will find information on tyre pressures for
the vehicle's factory-mounted tyres on the
plates described here.
Tyre pressure loss warning system
Important safety notes
While the vehicle is in motion, the tyre pres-
sure loss warning system monitors the set
tyre pressure using the rotational speed of
the wheels. This enables the system to detect
significant pressure loss in a tyre. If the speed
of rotation of a wheel changes as a result of
a loss of pressure, a corresponding warning
message will appear in the multifunction dis-
play.
G WARNING
The tyre pressure loss warning system does
not warn you of an incorrectly set tyre pres-
sure. The table on the inside of the fuel filler
flap will help you decide whether the tyre
pressures should be corrected.
The tyre pressure loss warning system does
not replace the need to regularly check your
vehicle's tyre pressures, since an even loss of
pressure on several tyres at the same time
cannot be detected by the tyre pressure loss
warning system.
The tyre pressure monitor is not able to warn
you of a sudden loss of pressure, e.g. if the
tyre is penetrated by a foreign object.
In the event of a sudden loss of pressure, bring
the vehicle to a halt by braking carefully. Do
not make any sudden steering movements
when doing so.
The function of the tyre pressure loss warning
system is limited or delayed if:
snow chains are fitted to your vehicle's
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tyres.
road conditions are wintry.
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