Some tire pressure tables show only the rim
diameters instead of the full tire size, e.g.
R18 . Rim diameter is part of the tire size and
can be found on the tire sidewall
( Y
page 357).
If the tire pressures have been set to the
lower values for lighter loads and/or lower
road speeds, the pressures should be reset to
the higher values: R
if you want to drive with an increased load
and/or R
if you want to drive at higher road speeds
i The tire pressures for increased loads
and/or higher road speeds, shown in the
tire pressure table, may have a negative
effect on driving comfort.
If the tire pressure is not set correctly, this
can lead to an excessive build-up of heat and
a sudden loss of pressure.
For more information, contact a qualified spe-
cialist workshop.
Important notes on tire pressure
G WARNING
If the tire pressure drops repeatedly, the
wheel, valve or tire may be damaged. Tire
pressure that is too low may result in a tire
blow-out. There is a risk of an accident. R
Check the tire for foreign objects. R
Check whether the wheel is losing air or the
valve is leaking. If you are unable to rectify the damage, con-
tact a qualified specialist workshop.
G WARNING
If you fit unsuitable accessories onto tire
valves, the tire valves may be overloaded and
malfunction, which can cause tire pressure
loss. Due to their design, retrofitted tire pres-
sure monitors keep the tire valve open. This
can also result in tire pressure loss. There is a
risk of an accident.
Only screw the standard valve cap or other
valve caps approved by Mercedes-Benz for
your vehicle onto the tire valve.
Use a suitable pressure gauge to check the
tire pressure. The outer appearance of a tire
does not permit any reliable conclusion about
the tire pressure. On vehicles equipped with
the electronic tire pressure monitor, the tire
pressure can be checked in the on-board
computer.
The tire temperature and pressure increase
when the vehicle is in motion. This is depend-
ent on the driving speed and the load.
Therefore, you should only correct tire pres-
sures when the tires are cold.
The tires are cold: R
if the vehicle has been parked with the tires
out of direct sunlight for at least three
hours and R
if the vehicle has not been driven further
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 ‡ (10 †), the tire pressure
changes by approxi mately 10 kPa (0.1 bar/
1.5 psi). Take this into account when check-
ing the pressure of warm tires. 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 result-
ing value will be higher than if the tires were
cold. This is normal. Do not reduce the tire Tire pressure 345
Wheels and tires Z
set the correct tire pressure. If an incorrect
tire pressure is set, these incorrect values
will be monitored. X
Also observe the notes in the section on tire
pressures ( Y
page 343).X
Make sure that the SmartKey is in position
2 in the ignition lock ( Y
page 149).X
Press Y or e on the steering wheel
to select the Serv.
menu.X
Press the c or d button to select
Tire Pressure
.X
Press the v button.
The Run Flat Indicator Active
Press 'OK' to Restart message
appears in the multifunction display.
If you wish to confirm the restart: X
Press the v button.
The Tire Pressure Now OK?
message
appears in the multifunction display. X
Press the c or d button to select
Yes
. X
Press the v button.
The Run Flat Indicator Restarted
message appears in the multifunction dis-
play.
After a teach-in period, the tire pressure
loss warning system will monitor the set
tire pressures of all four tires.
If you wish to cancel the restart: X
Press the 8 button.
or X
If the Tire Pressure Now OK? message
appears, press the c or d button to
select Cancel .X
Press the v button.
The tire pressure values stored at the last
restart will continue to be monitored. Tire pressure monitor
General notes If a tire pressure monitor is installed, the vehi-
cle's wheels have sensors that monitor the
tire pressures in all four tires. The tire pres-
sure monitor warns you if the pressure drops
in one or more of the tires. The tire pressure
monitor only functions if the corresponding
sensors are installed in all wheels.
Information on tire pressures is displayed in
the multifunction display. After a few minutes
of driving, the current tire pressure of each
tire is shown in the Serv. menu of the multi-
function display, see illustration (example).
For information on the message display, refer
to the "Checking the tire pressure electroni-
cally" section ( Y
page 350).
Important safety notes
G WARNING
Each tire, including the spare (if provided),
should be checked at least once every two
weeks when cold and inflated to the pressure
recommended by the vehicle manufacturer
on the Tire and Loading Information placard
on the driver's door B-pillar or the tire pres-
sure label on the inside of the fuel filler flap. If
your vehicle has tires of a different size than
the size indicated on the Tire and Loading
Information placard or, if available, the tire
pressure label, you should determine the
proper tire pressure for those tires.
As an added safety feature, your vehicle has
been equipped with a tire pressure monitoring
system (TPMS) that illuminates a low tire pres-
sure telltale when one or more of your tires
are significantly underinflated. Accordingly,348
Tire pressure
Wheels and tires