Page 345 of 539

344 OperationTires and wheelsCertification label
Even after careful determination of the
combined weight of all occupants, cargo
and the trailer tongue load (if applicable)
(page 344) as to not exceed the permis-
sible load limit, you must make sure that
your vehicle never exceeds the Gross
Vehicle Weight Rating (GVWR) and the
Gross Axle Weight Rating (GAWR) for ei-
ther the front or rear axle. You can obtain
the GVWR and GAWR from the
Certification label. The Certification Label
can be found on the driver’s door B-pillar,
see “Technical data” (
page 481).Gross Vehicle Weight Rating (GVWR): The
total weight of the vehicle, all occupants,
all cargo, and the trailer tongue load
(
page 344) must never exceed the
GVWR.
Gross Axle Weight Rating (GAWR): The to-
tal allowable weight that can be carried by
a single axle (front or rear).
To assure that your vehicle does not ex-
ceed the maximum permissible weight
limits (GVWR and GAWR for front and rear
axle), have the loaded vehicle (including
driver, passengers and all cargo and, if ap-
plicable, trailer fully loaded) weighed on a
suitable commercial scale.Trailer tongue load
The tongue load of any trailer is an impor-
tant weight to measure because it affects
the load you can carry in your vehicle. If a
trailer is towed, the tongue load must be
added to the weight of all occupants riding
and any cargo you are carrying in the
vehicle. The tongue load typically is
between 10% and 15% of the trailer weight
and everything loaded in it.
For more information on trailer tongue
load, see “Loading a trailer” (
page 315).
Page 346 of 539

345 Operation
Tires and wheels
Recommended tire inflation pressure
Your vehicle is equipped with the
Certification label (Example B) which also
lists the recommended tire and rim sizes
as well as cold tire inflation pressures. Depending on production date, some vehi-
cles may also be equipped with a Tire and
Loading Information placard (Example A).
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 346).Placard (Example A)
1Tire and Loading Information placard
with recommended cold tire inflation
pressures
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 347 of 539

346 OperationTires and wheelsPlacard (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.
Placard (Example B)
1Certification label with recommended
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.
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 348 of 539

347 Operation
Tires and wheels
Checking 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 339) or, if available, the inside
of the fuel filler flap. If necessary, add
air to achieve the recommended tire in-
flation pressure.
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.
Do not overload the tires by exceeding the
specified load limit as indicated on the plac-
ard on the driver’s door B-pillar. Overloading
the tires can overheat them, possibly caus-
ing a blowout.
Page 349 of 539

348 OperationTires and wheels
Install the valve cap.
Repeat this procedure for each tire.Run Flat Indicator
While the vehicle is being driven, the Run
Flat Indicator monitors the set tire inflation
pressures by evaluating each wheel’s rota-
tional speed. This allows the system to de-
tect a significant loss of pressure in a tire.
If a wheel’s rotational speed changes due
to falling tire inflation pressure, you will
see a corresponding warning message in
the multifunction display.
The Run Flat Indicator may function in a re-
stricted manner or with a delay if:
snow chains are mounted to the
vehicle
winter road conditions prevail
you are driving on a loose surface (e.g.
sand or gravel)
you are driving in a very sporty manner
(involving rapid acceleration or high
speeds in curves)
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.
Warning!
G
When the multifunction display shows the
message
Tire pressure Check tires
,
one or more of your tires is significantly un-
der-inflated. You should stop 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.
Page 350 of 539

349 Operation
Tires and wheels
iThe recommended tire inflation pres-
sures for your vehicle can be found on
the tire placard located on the driver’s
door B-pillar (
page 339). The tire in-
flation pressures are not listed in the
owner’s manual.
Warning!
G
The Run Flat Indicator does not indicate a
warning for wrongly selected tire inflation
pressures. Always adjust tire inflation pres-
sure according to the placard on the driver’s
door B-pillar or fuel filler flap.
The Run Flat Indicator does not replace reg-
ular checks of the tire inflation pressures
since a gradual pressure loss in all four tires
cannot be detected by the Run Flat
Indicator.
The Run Flat Indicator is not able to issue a
warning due to a sudden dramatic 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 apply-
ing the brakes and avoiding abrupt steering
maneuvers.
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.
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.
Page 351 of 539

350 OperationTires and wheelsReactivating the Run Flat Indicator
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.
Switch on the ignition (
page 34).
Make sure the standard display menu
appears in the multifunction display
(
page 150).
Press buttonk orj repeatedly
until the following message appears in
the multifunction display:
Press buttonæ.
The following message will appear in
the multifunction display:Tire pressure OK now?
If you wish to confirm activation:
Press buttonæ.
The following message will appear in
the multifunction display:Run Flat Indicator
reactivated
After a certain “learning phase”, the Run
Flat Indicator checks the set pressure val-
ues for all four tires.
If you wish to cancel activation:
Press buttonç.
or
Wait until the messageTire pressure OK now?disappears.
Warning!
G
The Run Flat Indicator can only warn you in
a reliable manner if you have set the correct
tire inflation pressures for each tire.
If an incorrect tire inflation pressure was
set, the system will monitor the pressure ac-
cording to the incorrect value.
Page 352 of 539

351 Operation
Tires and wheels
Checking tire pressure electronically
with the Advanced Tire Pressure Moni-
toring System* (Advanced TPMS*)The TPMS only functions on wheels that
are equipped with the proper electronic
sensors. It monitors the tire inflation pres-
sure, as selected by the driver, in all four
tires. A warning is issued to alert you to a
decrease in pressure in one or more of the
tires.
Tire pressure inquiries are made using the
multifunction display.The present inflation
pressures are displayed only after a few
minutes’ travel time.
Switch on the ignition (
page 34).
Press thej or kbutton until
the current inflation pressures for each
tire appear in the multifunction display.
iThe Advanced T
ire P
ressure M
onitoring
S
ystem* (Advanced TPMS*) is
equipped with a combination low tire
pressure/TPMS malfunction telltale in
the instrument cluster (
page 24). De-
pending on how the telltale illuminates,
it indicates a low tire pressure condi-
tion or a malfunction in the TPMS sys-
tem itself:
If the telltale illuminates continu-
ously, one or more of your tires is
significantly under-inflated. There is
no malfunction in the TPMS.
If the telltale flashes for 60 seconds
and then stays illuminated, the
TPMS system itself is not operating
properly.
iPossible differences between the read-
ings of a tire pressure gauge of an air
hose, e.g. gas station equipment, and
the vehicle’s control system can occur.
Usually the readings issued by the con-
trol system are more precise.
iWhen the message
Tire pressure
display appears after driving sev-
eral minutes
appears in the display,
the individual inflation pressure values
are matched with the tires. The individ-
ual values are displayed after a few
minutes driving.
iWith a spare wheel without wheel sen-
sor mounted, the system may still indi-
cate the tire inflation pressure of the
removed wheel for some minutes. If
this happens, keep in mind that the in-
dicated value where the spare wheel is
mounted does not reflect the actual
spare tire inflation pressure.