
Some tire pressure tables show only the rim
diameters instead of the full tire size, e.g.R18. The rim diameter is part of the tire size
and can be found on the tire sidewall( Y page 328).
If the tire pressures have been set to the
lower values for lighter loads and/or lower
road speeds, the pressures should be reset to the higher values:
R if you want to drive with an increased load
and/or
R if you want to drive at higher road speeds
iThe tire pressures for increased loads
and/or higher road speeds, shown in the
tire pressure table, may have a negative
effect on driving comfort.
If the tire pressure is not set correctly, this
can lead to an excessive build up of heat and
a sudden loss of pressure.
For more information, contact a qualified spe- cialist workshop.
Important notes on tire pressure
GWARNING
If the tire pressure drops repeatedly, the
wheel, valve or tire may be damaged. Tire
pressure that is too low may result in a tire
blow-out. There is a risk of an accident.
R Check the tire for foreign objects.
R Check whether the wheel is losing air or the
valve is leaking.
If you are unable to rectify the damage, con-
tact a qualified specialist workshop.
GWARNING
If you fit unsuitable accessories onto tire
valves, the tire valves may be overloaded andmalfunction, which can cause tire pressure
loss. Due to their design, retrofitted tire pres- sure monitors keep the tire valve open. This
can also result in tire pressure loss. There is a
risk of an accident.
Only screw the standard valve cap or other
valve caps approved by Mercedes-Benz for
your vehicle onto the tire valve.
Use a suitable pressure gauge to check the
tire pressure. The outer appearance of a tire
does not permit any reliable conclusion about the tire pressure. On vehicles equipped with
the electronic tire pressure monitor, the tire
pressure can be checked in the on-board
computer.
The tire temperature and pressure increase
when the vehicle is in motion. This is depend-
ent on the driving speed and the load.
Therefore, you should only correct tire pres-
sures when the tires are cold.
The tires are cold:
R if the vehicle has been parked with the tires
out of direct sunlight for at least three
hours and
R if the vehicle has not been driven further
than 1 mile (1.6 km)
The tire temperature changes depending on
the outside temperature, the vehicle speed
and the tire load. If the tire temperature
changes by 18 ‡ (10 †), the tire pressure
changes by approximately 10 kPa (0.1 bar/
1.5 psi). Take this into account when check-
ing the pressure of warm tires. Only correct
the tire pressure if it is too low for the current
operating conditions. If you check the tire
pressure when the tires are warm, the result- ing value will be higher than if the tires were
cold. This is normal. Do not reduce the tire
Tire pressure317
Wheels and tires
Z

pressure to the value specified for cold tires.The tire pressure would otherwise be too low.
Observe the recommended tire pressures for
cold tires:
R on the Tire and Loading Information placard
on the B-pillar on the driver's side
R in the tire pressure table on the inside of the
fuel filler flap
R printed in yellow on the rim of the emer-
gency/collapsible spare wheel (depending
on vehicle equipment)
Underinflated or overinflated tires
Underinflation
GWARNING
Tires with pressure that is too low can over-
heat and burst as a consequence. In addition, they also suffer from excessive and/or irreg-
ular wear, which can severely impair the brak-ing properties and the driving characteristics.There is a risk of an accident.
Avoid tire pressures that are too low in all the
tires, including the spare wheel.
Underinflated tires may:
R overheat, leading to tire defects
R have an adverse effect on handling charac-
teristics
R wear quickly and unevenly
R have an adverse effect on fuel consumption
Overinflation
GWARNING
Tires with excessively high pressure can burst
because they are damaged more easily by
road debris, potholes etc. In addition, they
also suffer from irregular wear, which can
severely impair the braking properties and the
driving characteristics. There is a risk of an
accident.
Avoid tire pressures that are too high in all the
tires, including the spare wheel. Overinflated tires may:
R increase the braking distance
R have an adverse effect on handling charac-
teristics
R wear quickly and unevenly
R have an adverse effect on ride comfort
R be 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( Y page 315).
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 ( Y page 315).
Information on air pressure for the tires on
your vehicle can be found:
R on the vehicle's Tire and Loading Informa-
tion placard on the B-pillar
R on the tire pressure label on the fuel fillerflap
R in the "Tire pressure" section
318Tire pressure
Wheels and tires

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.
X Press the tire pressure gauge securely onto
the valve.
X Read the tire pressure and compare it to
the recommended value on the Tire and
Loading Information placard or the tire
pressure table ( Ypage 315).
X If the tire pressure is too low, increase the
tire pressure to the recommended value.
X If 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.
X Screw the valve cap onto the valve.
X Repeat these steps for the other tires.
Tire pressure loss warning system
(Canada only)
General notes
While the vehicle is in motion, the tire pres-
sure loss warning system monitors the set
tire pressure 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 dis- play.
You can recognize the tire pressure loss warn-
ing by the
Run Flat Indicator Active
Press 'OK' to Restartmessage which
appears in the
Serv.menu of the multifunc-
tion display. Information on the message dis-
play can be found in the "Restarting the tire
pressure loss warning system" section( Y page 319).
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 315).
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 same time cannot be detected bythe tire pressure 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 maneuvers.
The function of the tire pressure loss warning
system is limited or delayed if:
R snow chains are mounted on your vehicle's
tires.
R road conditions are wintry.
R you are driving on sand or gravel.
R you adopt a very sporty driving style (cor-
nering at high speeds or driving with high
rates of acceleration).
R you drive with a heavy load.
Restarting the tire pressure loss warn-
ing system
Restart the tire pressure loss warning system
if you have: R changed the tire pressure
R changed the wheels or tires
R mounted new wheels or tires
X Before 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. Additionally, 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 incorrect
Tire pressure319
Wheels and tires
Z

tire pressure is set, these incorrect values
will be monitored.
X Also observe the notes in the section on tire
pressures ( Ypage 315).
X Make sure that the SmartKey is in position
2 in the ignition lock ( Ypage 139).
X Press the =or; button on the steer-
ing wheel to select the
Serv.menu.
X Press the 9or: button to select
Tire Pressure.
X Press the abutton.
The
Run Flat Indicator Active
Press 'OK' to Restartmessage
appears in the multifunction display.
If you wish to confirm the restart: X Press the abutton.
The
Tire Pressure Now OK?message
appears in the multifunction display.
X Press the 9or: button to select
Yes.
X Press the abutton.
The
Run Flat Indicator Restarted
message appears in the multifunction dis-
play.
After a teach-in period, the tire pressure
loss warning system will monitor the set
tire pressures of all four tires.
If you wish to cancel the restart: X Press the %button.
or
X If the
Tire Pressure Now OK?message
appears, use the 9or: button to
select
Cancel.
X Press 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 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
Servicemenu of the mul-
tifunction display.
Example: current tire pressure display
For information on the message display, refer to the "Checking the tire pressure electroni-
cally" section ( Ypage 322).
Important safety notes
GWARNING
Each tire, including the spare (if provided),
should be checked at least once a month
when cold and inflated to the pressure rec-
ommended by the vehicle manufacturer on
the Tire and Loading Information placard on
the driver's door B-pillar or the tire pressure
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 Infor-
mation placard or 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 monitoringsystem (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 illuminates,
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
320Tire pressure
Wheels and tires

reduces fuel efficiency and tire tread life, andmay affect the vehicle's handling and stop-
ping ability.
Please note that the TPMS is not a substitute for proper tire maintenance, and it is the driv-
er's responsibility to maintain correct tire
pressure, even if underinflation has not
reached the level to trigger illumination of the
TPMS low tire pressure telltale.
Your vehicle has also been equipped with a
TPMS malfunction indicator to indicate if the
system is not operating properly. The TPMS
malfunction indicator is combined with the
low tire pressure telltale. When the system
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 malfunctionexists.
When the malfunction indicator is illuminated,
the system may not be able to detect or signal
low tire pressure as intended. TPMS malfunc- tions may occur for a variety of reasons,
including the installation of incompatible
replacement or alternate tires or wheels on
the vehicle that prevent the TPMS from func-
tioning properly. Always check the TPMS mal-
function telltale after replacing one or more
tires or wheels on your vehicle to ensure that
the replacement or alternate tires and wheelsallow the TPMS to continue to function prop-
erly.
It is the driver's responsibility to set the tire
pressure to that recommended for cold tires
which is suitable for the operating situation( Y page 315). Note that the correct tire pres-
sure 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 pressure monitor after adjust-
ing the pressure of the cold tires( Y page 322). The current pressures are
saved as new reference values. As a result, a warning message will appear if the tire pres-
sure drops significantly.
The tire pressure monitor does not warn you
of an incorrectly set tire pressure. Observe
the notes on the recommended tire pressure
( Y page 315).
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 maneuvers.
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:
R if 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.
R if the warning lamp flashes for around a
minute and then remains lit constantly, the
tire pressure monitor is malfunctioning.
iIn addition to the warning lamp, a mes-
sage appears in the multifunction display.
Observe the information on display mes-
sages ( Ypage 236).
It may take up to ten minutes for you to be
informed about a malfunction in the tire pres-
sure monitor. The tire pressure warning lamp informs you about the malfunction by flashing
for approximately 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
Tire pressure321
Wheels and tires
Z

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
X Make sure that the SmartKey is in position
2 in the ignition lock ( Ypage 139).
X Press the =or; button on the steer-
ing wheel to select the
Serv.menu.
X Press the 9or: button to select
Tire Pressure.
X Press the abutton.
The current tire pressure of each tire is
shown in the multifunction display.
If the vehicle has been parked for over
20 minute s,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.
iIf an emergency spare wheel is mounted,
the system may continue to show the tire
pressure of the wheel that has been
removed for a few minutes. If this occurs,
note that the value displayed for the posi-
tion where the spare wheel is mounted is
not the same as the current tire pressure of
the emergency spare wheel.
Tire pressure monitor warning mes-
sages
If the tire pressure monitor detects a pressure loss in one or more tires, a warning message
is shown in the multifunction display and the yellow tire pressure monitor warning lamp
comes on.
R If the
Please Correct Tire Pressure
message appears in the multifunction dis-
play, the tire pressure in at least one tire is
too low and must be corrected at the next
opportunity.
R If the
CheckTiresmessage appears in the
multifunction display, the tire pressure in
one or more tires has dropped significantly and the tires must be checked.
R If the
Warning Tire Malfunction
appears in the multifunction display, the
tire pressure in one or more tires has drop-
ped suddenly and the tires must be
checked.
Observe the instructions and safety notes in
the display messages in the "Tires" section( Y page 236).
iIf the wheel positions on the vehicle are
rotated, the tire pressures may be dis-
played for the wrong positions for a short
time. This is rectified after a few minutes of driving, and the tire pressures are displayedfor the correct positions.
Restarting the tire pressure monitor
When you restart the tire pressure monitor, allexisting warning messages are deleted and
the warning lamp goes 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.
X Set the tire pressure to the value recom-
mended for the corresponding driving sit-
322Tire pressure
Wheels and tires

uation on the Tire and Loading Information
placard on the driver's side
B-pillar ( Ypage 315).
Additional tire pressure values for different loads can also be found on the tire pressure
table on the inside of the fuel filler flap( Y page 315).
X Make sure that the tire pressure is correct
on all four wheels.
X Make sure that the SmartKey is in position
2 in the ignition lock.
X Press the =or; button on the steer-
ing wheel to select the
Serv.menu.
X Press the 9or: button to select
Tire Pressure.
X Press the abutton.
The multifunction display shows the cur-
rent tire pressure for the individual tires or
the
Tirepressurewillbedisplayed
after driving a few minutesmes-
sage.
X Press the :button.
The
Use Current Pressures as New
Reference Valuesmessage appears in
the multifunction display.
If you wish to confirm the restart: X Press 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: X Press 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
CountryRadio type approval number
USAFCC ID: MRXMW2433A
FCC ID: MRXGG4
FCC ID: MRXMC34MA4
CanadaIC: 2546A-MW2433A
IC: 2546A-GG4
IC: 2546A-MC34MA4
Loading the vehicle
Instruction labels for tires and loads
GWARNING
Overloaded tires can overheat, causing a
blowout. Overloaded tires can also impair the steering and driving characteristics and lead
to brake failure. There is a risk of accident.
Observe the load rating of the tires. The load
rating must be at least half of the GAWR of
your vehicle. Never overload the tires by
exceeding the maximum load.
Two instruction labels on your vehicle show
the maximum possible load.
(1) The Tire and Loading Information placard is on the B-pillar on the driver's side. The
Tire and Loading Information placard
shows the maximum permissible number
of occupants and the maximum permis-
sible vehicle load. It also contains details
of the tire sizes and corresponding pres-
sures for tires mounted at the factory.
(2) The vehicle identification plate is on the B-pillar on the driver's side. The vehicle
identification plate informs you of the
gross vehicle weight rating. It is made up
of the vehicle weight, all vehicle occu-
pants, the fuel and the cargo. You can
also find information about the maximum gross axle weight rating on the front and
rear axle.
Loading the vehicle323
Wheels and ti res
Z

The maximum gross axle weight rating isthe maximum weight that can be carried
by one axle (front or rear axle). Never
exceed the maximum load or the maxi-
mum gross axle weight rating for the
front or rear axle.
:B-pillar, driver's side
Maximum permissible gross vehicle
weight rating
X Specification for maximum gross vehicle weight :is listed in the Tire and Loading
Information placard: "The combined weight of occupants and cargo should never
exceed XXX kilograms or XXX lbs."
The gross weight of all vehicle occupants,
load and luggage must not exceed the speci-
fied value.
iThe specifications shown on the Tire and
Loading Information placard in the illustra-
tion are examples. The maximum permis-
sible gross vehicle weight rating is vehicle- specific and may differ from that in the illustration. You can find the valid maximum
permissible gross vehicle weight rating for
your vehicle on the Tire and Loading Infor-
mation placard.
Number of seats
Maximum number of seats :indicates the
maximum number of occupants allowed to
travel in the vehicle. This information can be
found on the Tire and Loading Informationplacard.
iThe specifications shown on the Tire and
Loading Information placard in the illustra-
tion are examples. The number of seats is
vehicle-specific and can differ from the
details shown. The number of seats in your vehicle can be found on the Tire and Load-
ing Information placard.
Determining the correct load limit
Step-by-step instructions
The following steps have been developed as
required of all manufacturers under Title 49,
Code of U.S. Federal Regulations, Part 575
pursuant to the "National Traffic and Motor
Vehicle Safety Act of 1966". X Step 1: Locate the statement "The com-
bined weight of occupants and cargo
should never exceed XXX kg or XXX lbs." on
324Loading the vehicle
Wheels and tires