
MOExtended tires (tires with run-flat
properties)
General notes
With MOExtended tires (tires with run flat
characteristics), you can continue to drive
your vehicle even if there is a total loss of
pressure in one or more tires. The affected
tire must not show any clearly visible damage.
You can recognize MOExtended tires by the
MOExtended marking which appears on the
sidewall of the tire. You will find this marking next to the tire size designation, the load-
bearing capacity and the speed index
(
Ypage 303).
MOExtended tires may only be used in con-
junction with an active tire pressure monitor.
If a pressure loss warning message
appears in the multifunction display:
Robserve the instructions in the display mes-
sages (
Ypage 200).
Rcheck the tire for damage.
Rif driving on, observe the following notes.
The driving distance possible in run-flat mode
is approximately 50 miles (80 km) when the
vehicle is partially laden and approximately
18 miles (30 km) when the vehicle is fully
laden.
In addition to the vehicle load, the driving dis-
tance possible depends upon:
Rvehicle speed
Rroad condition
Routside temperature
The driving distance possible in run-flat mode
may be reduced by extreme driving condi-
tions/maneuvers, or it can be increased
through a moderate style of driving.
The driving distance possible in run-flat mode
is counted from the moment the tire pressure
loss warning appears in the multifunction dis-
play.
You must not exceed a maximum speed of
50 mph (80 km/h). When replacing one or all tires, please
observe the following specifications for your
vehicle's tires:
Rsize
Rthe type and
Rthe "MOExtended" mark
If a tire has gone flat and cannot be replaced
with a MOExtended tire, a standard tire may
be used as a temporary measure. Make sure
that you use the proper size a
nd type (sum-
mer or winter tire).
Vehicles equipped with MOExtended tires are
not equipped with a TIREFIT kit at the factory.
It is therefore recommended that you addi-
tionally equip your vehicle with a TIREFIT kit if you mount tires that do not feature run-flat
properties, e.g. winter tires. A TIREFIT kit may
be obtained from a qualified specialist work-
shop.
Important safety notes
GWARNING
When driving in emergency mode, the driving
characteristics deteriorate, e.g. when corner-
ing, accelerating quickly and when braking.
There is a risk of an accident.
Do not exceed the stated maximum speed.
Avoid abrupt steering and driving maneuvers,
and driving over obstacles (curbs, potholes,
off-road). This applies in particular to a laden
vehicle.
Stop driving in emergency mode if:
Ryou hear banging noises.
Rthe vehicle starts to shake.
Ryou see smoke and smell rubber.
RESP®is intervening constantly.
Rthere are tears in the sidewalls of the tire.
After driving in emergency mode, have the
wheel rims checked at a qualified specialist
workshop with regard to their further use. The
defective tire must be replaced in every case.
272Flat tire
Roadside Assistance

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 rec-
ommended tire pressure for your vehicle
when adjusting the tire pressure
(
Ypage 291).
iThe actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
Checking the tire pressures
Important safety notes
Observe the notes on tire pressure
(
Ypage 291).
Information on air pressure for the tires on
your vehicle can be found:
Ron the vehicle's Tire and Loading Informa-
tion placard on the B-pillar
Ron the tire pressure label on the fuel filler
flap
Rin the "Tire pressure" section
Checking tire pressures manually
To determine and set the correct tire pres-
sure, 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 291).
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 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 Service
menu of the mul-
tifunction display, see illustration (example).
Example: Sedan, current tire pressure display
294Tire pressure
Wheels and tires

The tire pressure monitor has a yellow warn-
ing lamp in the instrument cluster for indicat-
ing a pressure loss or malfunction. Whether
the warning lamp flashes or lights up indi-
cates whether a tire pressure is too low or the
tire pressure monitor is malfunctioning:
Rif the warning lamp is lit continuously, the
tire pressure on one or more tires is signif- icantly too low. The tire pressure monitor is
not malfunctioning.
Rif the warning lamp flashes for around a
minute and then remains lit constantly, the
tire pressure monitor is malfunctioning.
In addition to the warning lamp, a message
appears in the multifunction display. Observe
the information on display messages
(
Ypage 200).
It may take up to ten minutes for a malfunc-
tion of the tire pressure monitor to be indica-
ted. A malfunction will be indicated by the tire
pressure warning lamp flashing for approx-
imately one minute and then remaining lit.
When the malfunction has been rectified, the
tire pressure warning lamp goes out after a
few minutes of driving.
The tire pressure values indicated by the on-
board computer may differ from those meas-
ured at a gas station with a pressure gauge.
The tire pressures shown by the on-board
computer refer to those measured at sea
level. At high altitudes, the tire pressure val-
ues indicated by a pressure gauge are higher
than those shown by the on-board computer.
In this case, do not reduce the tire pressures.
The operation of the tire pressure monitor can be affected by interference from radio trans-
mitting equipment (e.g. radio headphones,
two-way radios) that may be being operated
in or near the vehicle.
Checking the tire pressure electroni-
cally
XMake sure that the SmartKey is in position
2 in the ignition lock (
Ypage 137).
XPress the =or; button on the steer-
ing wheel to select the Service
menu.
XPress the9or: button to select
Tire Pressure
.
XPress the abutton.
The current tire pressure of each tire is
shown in the multifunction display.
If the vehicle has been parked for over
20 minutes, the Tire pressure will be
displayed after driving a few
minutesmessage appears.
After a teach-in process, the tire pressure
monitor automatically detects new wheels or
new sensors. As long as a clear allocation of
the tire pressure value to the individual
wheels is not possible, the Tire Pressure
Monitor Activedisplay message is shown
instead of the tire pressure display. The tire
pressures are already being monitored.
If an emergency spare wheel is mounted, the
system may continue to show the tire pres-
sure of the wheel that has been removed for a few minutes. If this occurs, note that the value
displayed for the position where the spare
wheel is mounted is not the same as the cur-
rent tire pressure of the emergency spare
wheel.
Tire pressure monitor warning mes-
sages
If the tire pressure monitor detects a pressureloss in one or more tires, a warning message
is shown in the multifunction display and the
yellow tire pressure monitor warning lamp
comes on.
RIf the Correct Tire Pressuremessage
appears in the multifunction display, the
tire pressure in at least one tire is too low
296Tire pressure
Wheels and tires

and must be corrected at the next oppor-
tunity.
RIf theCheckTiresmessage appears in the
multifunction display, the tire pressure in
one or more tires has dropped significantly
and the tires must be checked.
RIf the Warning Tire Malfunctionmes-
sage appears in the multifunction display,
the tire pressure in one or more tires has
dropped suddenly and the tires must be
checked.
Observe the instructions and safety notes in
the display messages in the "Tires" section
(
Ypage 200).
If the wheel positions on the vehicle are rota-
ted, the tire pressures may be displayed for
the wrong positions for a short time. This is
rectified after a few minutes of driving, and
the tire pressures are displayed for the cor-
rect positions.
Restarting the tire pressure monitor
When you restart the tire pressure monitor, all
existing warning messages are deleted and
the warning lamps go out. The monitor uses
the currently set tire pressures as the refer-
ence values for monitoring. In most cases, the
tire pressure monitor will automatically
detect the new reference values after you
have changed the tire pressure. However, you
can also define reference values manually as described here. The tire pressure monitor
then monitors the new tire pressure values.
XSet the tire pressure to the value recom-
mended for the corresponding driving sit-
uation on the Tire and Loading Information
placard on the driver's side
B-pillar (
Ypage 291).
Additional tire pressure values for different
loads can also be found on the tire pressure
table on the inside of the fuel filler flap
(
Ypage 291).
XMake sure that the tire pressure is correct
on all four wheels.
XMake sure that the SmartKey is in position
2 in the ignition lock.
XPress the =or; button on the steer-
ing wheel to select the Service
menu.
XPress the9or: button to select
Tire Pressure
.
XPress the abutton.
The multifunction display shows the cur-
rent tire pressure for the individual tires or
the Tire
pressurewillbedisplayed
after driving a few minutesmes-
sage.
XPress the :button.
The Use Current Pressures as New
Reference Valuesmessage appears in
the multifunction display.
If you wish to confirm the restart:
XPress the abutton.
The Tire Press. Monitor Restarted
message appears in the multifunction dis-
play.
After driving for a few minutes, the system
checks whether the current tire pressures
are within the specified range. The new tire
pressures are then accepted as reference
values and monitored.
If you wish to cancel the restart:
XPress the %button.
The tire pressure values stored at the last
restart will continue to be monitored.
Radio type approval for the tire pres-
sure monitor
In certain countries, a radio type approval for
the tire pressure monitor may be required.
The radio type approval number for the tire
pressure monitor can be found in the "Wheels
and tires" section of the Digital Operator's
Manual.
Tire pressure297
Wheels and tires
Z