333 Operation
Tires and wheels
Direction of rotation
Unidirectional tires offer added advan-
tages, such as better hydroplaning perfor-
mance. To benefit, however, you must
make sure the tires rotate in the direction
specified.
An arrow on the sidewall indicates the
intended direction of rotation (spinning) of
the tire.
Loading the vehicle
Two labels on your vehicle show how much
weight it may properly carry.
The Tire and Loading Information
placard (Example A) or the Vehicle Tire
Information placard (Example B) can be
found on the driver’s door B-pillar. This
placard tells you important information
about the number of people that can be
in the vehicle and the total weight that
can be carried in the vehicle. It also
contains information on the proper size
and recommended tire inflation
pressures for the original equipment
tires on your vehicle.
The Certification label, also found on
the driver’s door B-pillar tells you about
the gross weight capacity of your vehi-
cle, called the Gross Vehicle Weight
Rating (GVWR). The GVWR includes the
weight of the vehicle, all occupants,
fuel and cargo. The Certification label
also tells you about the front and rear axle weight capacity,
called the Gross Axle Weight Rating
(GAWR). The GAWR is the total allow-
able weight that can be carried by a sin-
gle axle (front or rear). Never exceed
the GVWR or GAWR for either the front
axle or rear axle.
1Driver’s door B-pillar
Following is a discussion on how to work
with the information contained on the two
placards with regards to loading your vehi-
cle.
iSpare wheels may be mounted against
the direction of rotation (spinning) even
with a unidirectional tire for temporary
use only until the regular drive wheel
has been repaired or replaced. Always
observe and follow applicable tempo-
rary use restrictions and speed limita-
tions indicated on the spare wheel.
339 Operation
Tires and wheels
Recommended 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 333).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 340).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
is specific to each vehicle and may vary
from data shown in the illustrations
below. Refer to placard on vehicle for
actual data specific to your vehicle.
340 OperationTires and wheelsPlacard (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
pressure information for vehicle loads less
than the maximum loaded vehicle condi-
tion. If such information is provided, it can
be found on the placard located on the in-
side 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.
341 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). If necessary, add air to
achieve the recommended tire inflation
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 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 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.
342 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)
Warning!
G
When the multifunction display shows the
message
Low pres. mode Check tire
Max. speed 50 mph
, one or more of your
tires is significantly under-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 vehi-
cle’s tire information placard. Driving on a
significantly under-inflated 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 vehi-
cle’s handling and stopping ability. Each tire,
including the spare, should be checked
monthly when cold and set to the recom-
mended tire inflation 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 (
page 333). The tire in-
flation pressures are not listed in the
owner’s manual.
343 Operation
Tires and wheels
Reactivating 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 144).
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 pres. now
OK?
No Yes
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
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.
344 OperationTires and wheelsIf 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 pres. now
OK?
No Yesdisappears.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
characteristicsOverinflated 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
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
overheated.
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.
345 Operation
Tires and wheels
MOExtended system*
The MOExtended system allows you to
continue driving your vehicle even if there
is a total loss of pressure in one or more
tires.
You may only use the MOExtended system
in conjunction with the Run Flat Indicator*
(page 342).
For information on driving in case of pres-
sure loss in one or more tires (emergency
mode), see the “Practical hints” section
(page 452).
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 353)
2DOT, Tire Identification Number (TIN)
(page 350)
3Maximum tire load (
page 351)
4Maximum tire inflation pressure
(
page 352)
5Manufacturer
6Tire ply material (
page 354)
7Tire size designation, load and speed
rating (
page 346)
8Load identification (
page 349)
9Tire name
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 471).