Page 265 of 409

264 OperationTires and wheelsRecommended tire inflation pressure
Your vehicle is equipped with either the
Tire and Loading Information placard
(Example A) or the Vehicle Tire Information
placard (Example B) located on the driver’s
door B-pillar (
page 258).The tire inflation pressure should be
checked regularly and should only be ad-
justed on cold tires. The tires can be con-
sidered cold if the vehicle has been parked
for at least three hours or driven less than
one mile (1.6 km).
Follow recommended cold tire inflation
pressures listed on placard.
Keeping the tires properly inflated
provides the best handling, tread life and
riding comfort.
In addition to the tire placard on the
driver’s door B-pillar, also consult the fuel
filler flap for any additional information
pertaining to special driving situations. For
more information, see “Important notes on
tire inflation pressure” (
page 265).Placard (Example A)
1Tire and Loading Information placard
with recommended cold tire inflation
pressures
Placard (Example A) lists the recommend-
ed cold tire inflation pressures for maxi-
mum loaded vehicle weight. The tire
inflation pressures listed apply to the tires
installed as original equipment.
Warning!
G
Follow recommended tire inflation
pressures.
Do not underinflate tires. Underinflated tires
wear excessively and/or unevenly,
adversely affect handling and fuel economy,
and are more likely to fail from being over-
heated.
Do not overinflate tires. Overinflated tires
can adversely affect handling and ride
comfort, wear unevenly, increase stopping
distance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road
debris, potholes etc.
iData shown on placard examples are
for illustration purposes only. Tire data
are specific to each vehicle and may
vary from data shown in the illustra-
tions below. Refer to placard on vehicle
for actual data specific to your vehicle.
Page 266 of 409

265 Operation
Tires and wheels
Placard (Example B)
1Vehicle Tire Information placard with
recommended cold tire inflation
pressures
Placard (Example B) lists the recommend-
ed cold tire inflation pressures for maxi-
mum loaded vehicle weight. The tire
inflation pressures listed apply to the tires
installed as original equipment.Important notes on tire inflation
pressure
Tire temperature and tire inflation pressure
are also increased while driving, depending
on the driving speed and the tire load.
If you will be driving your vehicle at high
speeds of 100 mph (160 km/h) or higher,
where it is legal and conditions allow,
consult the placard on the inside of the fuel
filler flap on how to adjust the cold tire in-
flation pressure. If you do not adjust the
tire inflation pressure, excessive heat can
build up and result in sudden tire failure.Be sure to readjust the tire inflation
pressure for normal driving speeds. You
should wait until the tires are cold before
adjusting the tire inflation pressure.
Some vehicles may have supplemental tire
inflation pressure information for vehicle
loads less than the maximum loaded vehi-
cle condition. If such information is provid-
ed, it can be found on the placard located
on the inside of the fuel filler flap.
Tire inflation pressure changes by approxi-
mately 1.5 psi (0.1 bar) per 18°F (10°C) of
air temperature change. Keep this in mind
when checking tire inflation pressure
where the temperature is different from
the outside temperature.
iPlacard (Example B) may list
recommended cold tire inflation
pressures for different vehicle loads.
Warning!
G
If the tire inflation pressure repeatedly
drops:
Check the tires for punctures from
foreign objects.
Check to see whether air is leaking from
the valves or from around the rim.
Page 267 of 409

266 OperationTires and wheelsChecking tire inflation pressure
Regularly check your tire inflation pressure
at least once a month.
Check and adjust the tire inflation
pressure when the tires are cold. The tires
can be considered cold if the vehicle has
been parked for at least three hours or
driven less than one mile (1.6 km).
If you check the tire inflation pressure
when the tires are warm (the vehicle has
been driven for several miles or sitting less
than three hours), the reading will be
approximately 4 psi (0.3 bar) higher than
the cold reading. This is normal. Do not let
air out to match the specified cold tire in-
flation pressure. Otherwise the tire will be
underinflated.Checking tire inflation pressure
manually
Follow the steps below to achieve correct
tire inflation pressure:
Remove the cap from the valve on one
tire.
Firmly press a tire gauge onto the
valve.
Read tire inflation pressure on tire
gauge and check against the recom-
mended tire inflation pressure on the
placard on the driver’s door B-pillar
(page 264). If necessary, add air to
achieve the recommended tire inflation
pressure.
Install the valve cap.
Repeat this procedure for each tire.iIf you have overfilled the tire, release
tire inflation pressure by pushing the
metal stem of the valve with e.g. a tip of
a pen. Then recheck the tire inflation
pressure with the tire gauge.
Page 268 of 409

267 Operation
Tires and wheels
Checking tire inflation 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
issued to alert you to a decrease in tire
inflation pressure in one or more of the
tires.
You can call up the tire inflation pressure
monitoring display using the control
system (
page 137).
Switch on the ignition (
page 40).
Press buttonè orÿ on the
multifunction steering wheel
repeatedly until the standard display
menu appears in the multifunction
display (
page 117).
Press button k repeatedly until the
current tire inflation pressures for each
tire appear in the multifunction display.
iAfter you have reactivated the tire infla-
tion pressure monitor, the current tire
inflation pressures will only be shown
after a few minutes driving time.
During this time you will see the
following message in the multifunction
display:Tire pressure
displayed only
after driving
a few minutesiPossible differences between the read-
ings of a tire inflation pressure gauge of
an air hose, e.g. gas station equipment,
and the vehicle’s control system can
occur. The readings issued by the
control system are more precise.
iYou can select the unit of measure
(bar/psi) used for the tire inflation
pressure by changing the setting in the
control system (
page 137).
Page 269 of 409

268 OperationTires and wheelsWarning!
G
When the tire inflation pressure monitoring
system warning light is lit, one or more of
your tires is significantly under-inflated. You
should stop in a safe location and check
your tires as soon as possible, and inflate
them to the proper tire inflation pressure as
indicated on the vehicle’s tire information
placard. Driving on a significantly under-in-
flated tire causes the tire to overheat and
can lead to tire failure. Under-inflation also
reduces fuel efficiency and tire tread life,
and may affect the vehicle’s handling and
stopping ability. Each tire, including the
spare, should be checked monthly when
cold and set to the recommended tire infla-
tion pressure as specified in the vehicle
placard and owner’s manual.
iThe recommended tire inflation pres-
sures for your vehicle can be found on
the tire placard located on the driver’s
door B-pillar. The tire inflation pres-
sures are not listed in the owner’s
manual.Warning!
G
The tire inflation pressure monitor does not
indicate a warning for wrongly selected tire
inflation pressures. Always adjust tire infla-
tion pressure according to the placard on
the driver’s door B-pillar or, if available, the
inside of the fuel filler flap.
The tire inflation pressure monitor is not
able to issue a warning due to a sudden dra-
matic loss of tire inflation pressure (e.g. tire
blowout caused by a foreign object). In this
case bring the vehicle to a halt by carefully
applying the brakes and avoiding abrupt
steering maneuvers.
iOperating radio transmission equip-
ment (e.g. wireless headsets, two-way
radios) in or near the vehicle could
cause the tire inflation pressure
monitor to malfunction.Warning!
G
Follow recommend tire inflation pressures.
Do not underinflate tires. Underinflated tires
wear excessively and/or unevenly,
adversely affect handling and fuel economy,
and are more likely to fail from being over-
heated.
Do not overinflate tires. Overinflated tires
can adversely affect handling and ride
comfort, wear unevenly, increase stopping
distance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road
debris, potholes etc.
Page 270 of 409

269 Operation
Tires and wheels
Reactivating the tire inflation pressure
monitor
The tire inflation pressure monitor must be
reactivated in the following situations:
If you have changed the tire inflation
pressure
If you have replaced the wheels or tires
If you have installed new wheels or
tires
Using the tire placard on the driver’s
door B-pillar or, if available, the inside
of the fuel filler flap, make sure the tire
inflation pressure of all four tires is cor-
rect.
Press button k repeatedly until you
see the current tire inflation pressures
for each tire appear in the multifunc-
tion display or the following message
appears in the multifunction display:Tire pressure
displayed only
after driving
a few minutes
Press the reset button on the instru-
ment cluster (
page 29).
The following message will appear in
the multifunction display:
Monitor current
tire pressure?
Do not overload the tires by exceeding the
specified load limit or vehicle capacity
weight as indicated on the placard on the
driver’s door B-pillar. Overloading the tires
can overheat them, possibly causing a
blowout.
iIf you are transporting a deflated tire
and/or additional wheel sensors in the
vehicle, do not activate the tire inflation
pressure monitor until
the deflated tire and/or additional
wheel sensors are no longer in the
vehicle
you have inflated the tire to the
correct tire inflation pressure
Page 271 of 409

270 OperationTires and wheels
Press button æ.
The following message will appear in
the multifunction display:Tire pres. monitor
reactivated
The tire inflation pressure monitor will
now monitor the tire inflation pressure
values of all four tires.
The following message will appear in
the multifunction display field:
Tire pressure
displayed only
after driving
a few minutesThis display appears until the individual
tire inflation pressure values are
matched with the tires. The individual
values are then displayed
(page 267).If you wish to cancel activation:
Press button ç.
If one of the following messages ap-
pears in the multifunction display:
Reactivate tire
pressure monitor
after rectifying
pressure
Tire pressure
Please rectify
Check the tire inflation pressures and
correct them if necessary.
Reactivate the tire inflation pressure
monitor.Potential problems associated with
underinflated and overinflated tires
Underinflated tire inflation pressure
Underinflated tires can:
cause excessive and uneven tire wear
adversely affect fuel economy
lead to tire failure from being
overheated
adversely affect handling
characteristicsWarning!
G
Follow recommended tire inflation
pressures.
Do not underinflate tires. Underinflated tires
wear excessively and/or unevenly,
adversely affect handling and fuel economy,
and are more likely to fail from being
overheated.
Page 272 of 409

271 Operation
Tires and wheels
Overinflated tire inflation pressure
Overinflated tires can:
adversely affect handling
characteristics
cause uneven tire wear
be more prone to damage from road
hazards
adversely affect ride comfort
increase stopping distance
Tire labeling
Besides tire name (sales designation) and
manufacturer name, a number of markings
can be found on a tire.
Following are some explanations for the
markings on your vehicle’s tires:1Uniform Quality Grading Standards
(
page 279)
2DOT, Tire Identification Number (TIN)
(page 276)
3Maximum tire load (
page 277)
4Maximum tire inflation pressure
(
page 278)
5Manufacturer
6Tire ply material (
page 281)
7Tire size designation, load and speed
rating (
page 272)
8Load identification (
page 275)
9Tire name
Warning!
G
Follow recommended tire inflation
pressures.
Do not overinflate tires. Overinflated tires
can adversely affect handling and ride
comfort, wear unevenly, increase stopping
distance, and result in sudden deflation
(blowout) because they are more likely to
become punctured or damaged by road
debris, potholes etc.
iFor illustration purposes only. Actual
data on tires are specific to each vehi-
cle and may vary from data shown in
above illustration.
For more information, see “Rims and
tires” (
page 371).