Mercedes-Benz E-Class 2009 Owner's Manual page 190

Rim diameter : is part of the tyre size and
can be found on the tyre sidewall.
G
Risk of accident
Tyre pressure that is either too high or too low
has a negative effect on the vehicle's driving
safety, which could lead you to cause an acci-
dent. Therefore, you should regularly check
the pressure of all the tyres, particularly prior
to long trips, and correct the pressure as nec-
essary.
Use a suitable pressure gauge. The outer
appearance of a tyre does not permit any reli-
able conclusion about the tyre pressure.
G
Risk of accident
Do not fit anything else to the tyre valve other
than the standard valve cap. In particular, ret-
rofitted tyre pressure monitors which are
screwed on to the valve may overload it and
cause it to fail. Due to their design, the valve
is kept open continuously, which may lead to
air loss.
G Risk of accident
Should the tyre pressure drop repeatedly:
check the tyre for foreign bodies.
R
check whether the wheel is losing air or the
R
valve is leaking.
make sure that only a valve cap approved
R
by Mercedes-Benz is fitted on the tyre
valve.
* optional
Tyres and wheels
Tyre pressures that are too low have a nega-
tive effect on vehicle safety, which could lead
you to cause an accident.
If possible, you should only correct tyre pres-
sures when the tyres are cold. 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 0.1 bar 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 condi-
tions.
Driving with tyre pressure that is too high or
too low can:
shorten the service life of the tyres
R
increase the likelihood of tyre damage
R
have a negative effect on handling charac-
R
teristics (e.g. by causing aquaplaning)
Also check the pressure of the "Minispare"
emergency spare wheel*.
H
Environmental note
Check the tyre pressure regularly, at least
every 14 days.
Tyre pressure loss warning
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 multi-function dis-
play.
G
Risk of accident
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.
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