Overinflated tires may:
Rincrease the braking distance
Radversely affect handling
Rwear excessively and/or unevenly
Rhave an adverse effect on ride comfort
Rbe more susceptible to damage
Maximum tire pressures
:Example: maximum permissible tire pres-
sure
Never exceed the maximum permissible tire
inflation pressure. Always observe the recom-
mended tire pressure for your vehicle when
adjusting the tire pressure (
Ypage 295).
iThe actual values for tires are vehicle-spe-
cific and may deviate from the values in the
illustration.
Checking the tire pressures
Important safety notes
Observe the notes on tire pressure
(Ypage 295).
Information on air pressure for the tires on your
vehicle can be found:
Ron the vehicle's Tire and Loading Information
placard on the B-pillar
Rin the tire pressure table in the fuel filler flap
(Ypage 139)
Rin the "Tire pressure" section
Checking tire pressures manually
To determine and set the correct tire pressure,
proceed as follows:
XRemove the valve cap of the tire that is to be
checked.
XPress the tire pressure gauge securely onto
the valve.
XRead the tire pressure and compare it to the
recommended value on the Tire and Loading
Information placard or the tire pressure table (
Ypage 295).
XIf the tire pressure is too low, increase the tire
pressure to the recommended value.
XIf the tire pressure is too high, release air. To
do so, press down the metal pin in the valve,
using the tip of a pen for example. Then check
the tire pressure again using the tire pressure
checker.
XScrew the valve cap onto the valve.
XRepeat these steps for the other tires.
Tire pressure loss warning system
(Canada only)
General notes
While the vehicle is in motion, the tire pressure
loss warning system monitors the set tire pres-
sure using the rotational speed of the wheels.
This enables the system to detect significant
pressure loss in a tire. 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 multifunction display.
You can recognize the tire pressure loss warning
by the Run Flat Indicator Active Press
'OK' to Restartmessage which appears in
the Serv.menu of the multifunction display.
Information on the message display can be
found in the "Restarting the tire pressure loss
warning system" section (
Ypage 299).
Important safety notes
The tire pressure warning system does not warn
you of an incorrectly set tire pressure. Observe
the notes on the recommended tire pressure
(
Ypage 295).
The tire pressure loss warning does not replace
the need to regularly check the tire pressure. An
even loss of pressure on several tires at the
298Tire pressure
Wheels and tires
same time cannot be detected by the tire pres-
sure loss warning system.
The tire pressure monitor is not able to warn you
of a sudden loss of pressure, e.g. if the tire is
penetrated by a foreign object. In the event of a
sudden loss of pressure, bring the vehicle to a
halt by braking carefully. Avoid abrupt steering
movements.
The function of the tire pressure loss warning
system is limited or delayed if:
Rsnow chains are mounted on your vehicle's
tires.
Rroad conditions are wintry.
Ryou are driving on sand or gravel.
Ryou adopt a very sporty driving style (corner-
ing at high speeds or driving with high rates ofacceleration).
Ryou are driving with a heavy load (in the vehi-cle or on the roof).
Restarting the tire pressure loss warn-
ing system
Restart the tire pressure loss warning system if
you have:
Rchanged the tire pressure
Rchanged the wheels or tires
Rmounted new wheels or tires
XBefore restarting, make sure that the tire
pressures are set properly on all four tires for
the respective operating conditions.
The recommended tire pressure can be found
on the Tire and Loading Information placard
on the B-pillar on the driver's side. Addition-
ally, a tire pressure table is attached to the
fuel filler flap. The tire pressure loss warning
system can only give reliable warnings if you
have set the correct tire pressure. If an incor-
rect tire pressure is set, these incorrect val-
ues will be monitored.
XAlso observe the notes in the section on tire
pressures (Ypage 295).
XMake sure that the SmartKey is in position 2
in the ignition lock (Ypage 123).
XPress the =or; button on the steering
wheel to select the Serv.menu.
XPress the9or: button on the steering
wheel to select the Tire Pressuremenu.
XPress theabutton.
The Run Flat Indicator Active Press
'OK' to Restartmessage appears in the
multifunction display.
If you wish to confirm the restart:
XPress the abutton.
The Tire Pressure Now OK?message
appears in the multifunction display.
XPress the 9or: button to select Yes.
XPress theabutton.
The Run Flat Indicator Restartedmes-
sage appears in the multifunction display.
After a teach-in period, the tire pressure loss
warning system will monitor the set tire pres-
sures of all four tires.
If you wish to cancel the restart:
XPress the %button.
or
XWhen the TirePressureNowOK?message
appears, press the 9or: button to
select Cancel
.
XPress the abutton.
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 pressure mon-
itor 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 Service
menu of the multifunction
display, see illustration (example).
Tire pressure299
Wheels and tires
Z
For information on the message display, refer to
the "Checking the tire pressure electronically"
section (
Ypage 301).
Important safety notes
GWARNING
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,
when the low tire pressure telltale lights up,
you should stop and check your tires as soon
as possible, and inflate them to the proper
pressure. Driving on a significantly underin-
flated tire causes the tire to overheat and can
lead to tire failure.
Underinflation also reduces fuel efficiency
and tire tread life, and may affect the vehicle's
handling and stopping ability. Please note thatthe TPMS is not a substitute for proper tire
maintenance, and it is the driver's responsi-
bility to maintain correct tire pressure, even if
underinflation has not reached the level to
trigger illumination of the TPMS low tire pres-
sure telltale.
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate when
the system is not operating properly. The
TPMS malfunction indicator is combined withthe low tire pressure telltale. When the sys-
tem detects a malfunction, the warning lamp
will flash for approximately a minute and then
remain continuously illuminated. This
sequence will be repeated every time the vehi-
cle is started as long as the malfunction
exists. When the malfunction indicator is illu-
minated, the system may not be able to detect
or signal low tire pressure as intended.
TPMS malfunctions may occur for a variety of
reasons, including the installation of incom-
patible replacement or alternate tires or
wheels on the vehicle that prevent the TPMS
from functioning properly. Always check the
TPMS malfunction telltale after replacing one
or more tires or wheels on your vehicle to
ensure that the replacement or alternate Tires
and wheels allow the TPMS to continue to
function properly.
It is the driver's responsibility to set the tire
pressure to that recommended for cold tires
which is suitable for the operating situation
(
Ypage 295). Note that the correct tire pressure
for the current operating situation must first be
taught-in to the tire pressure monitor. If there is
a substantial loss of pressure, the warning
threshold for the warning message is aligned to
the reference values taught-in. Restart the tire
pre ssure moni
tor after adjusting the pressure of
the cold tires (Ypage 302). The current pres-
sures are saved as new reference values. As a
result, a warning message will appear if the tire pressure drops significantly.
The tire pressure monitor does not warn you of
an incorrectly set tire pressure. Observe the
notes on the recommended tire pressure
(
Ypage 295).
The tire pressure monitor is not able to warn you
of a sudden loss of pressure, e.g. if the tire is
penetrated by a foreign object. In the event of a
sudden loss of pressure, bring the vehicle to a
halt by braking carefully. Avoid abrupt steering
movements.
300Tire pressure
Wheels and tires
Weight of optional extras
The combined weight of those optional extras
that weigh more than the replaced standard
parts and more than 2.3 kg (5 lbs). These
optional extras, such as high-performance
brakes, level control, a roof rack or a high-per-
formance battery, are not included in the curb
weight and the weight of the accessories.
TIN (Tire Identification Number)
This is a unique identifier which can be used by
a tire manufacturer to identify tires, for example
for a product recall, and thus identify the pur-
chasers. The TIN is made up of the manufactur-
er's identity code, tire size, tire type code and
the manufacturing date.
Load bearing index
The load bearing index (also load index) is a code
that contains the maximum load bearing capa-
city of a tire.
Traction
Traction is the result of friction between the tires
and the road surface.
Treadwear indicators
Narrow bars (tread wear bars) that are distrib-
uted over the tire tread. If the tire tread is level
with the bars, the wear limit of áin (1.6 mm)
has been reached.
Occupant distribution
The distribution of occupants in a vehicle at their
designated seating positions.
Total load limit
Nominal load and luggage load plus 68 kg
(150 lbs) multiplied by the number of seats in
the vehicle.
Changing a wheel
Flat tire
The "Breakdown assistance" section
(Ypage 278) contains information and notes on
how to deal with a flat tire. Information on driv-
ing with MOExtended tires in the event of a flat
tire can be found under "MOExtended tires (tires
with run-flat characteristics" (
Ypage 278).
Vehicle with emergency spare wheel: in the
event of a flat tire, the emergency spare wheel is mounted as described under "Mounting a
wheel" (
Ypage 313).
Rotating the wheels
GWARNING
Interchanging the front and rear wheels may
severely impair the driving characteristics if
the wheels or tires have different dimensions. The wheel brakes or suspension components
may also be damaged. There is a risk of acci-
dent.
Rotate front and rear wheels only if the wheels and tires are of the same dimensions.
!On vehicles equipped with a tire pressure
monitor, electronic components are located
in the wheel.
Tire-mounting tools should not be used near
the valve. This could damage the electronic
components.
Only have tires changed at a qualified spe-
cialist workshop.
Always observe the instructions and safety
notes in the "Mounting a wheel" section
(
Ypage 313).
The wear patterns on the front and rear tires
differ, depending on the operating conditions.
Rotate the wheels before a clear wear pattern
has formed on the tires. Front tires typically
wear more on the shoulders and the rear tires in
the center.
On vehicles that have the same size front and
rear wheels, you can rotate the wheels accord-
ing to the intervals in the tire manufacturer's
warranty book in your vehicle documents. If no
warranty book is available, the tires should be
rotated every 3,000 to 6,000 miles (5,000 to
10,000 km). Depending on tire wear, this may
be required earlier. Do not change the direction
of wheel rotation.
Clean the contact surfaces of the wheel and the
brake disc thoroughly every time a wheel is rota- ted. Check the tire pressure and, if necessary,
restart the tire pressure loss warning system
(
Ypage 299) or the tire pressure monitor
(Ypage 302).
312Changing a wheel
Wheels and tires