Page 369 of 410

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
(
Ypage 377).
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:
Rif you want to drive with an increased load
and/or
Rif 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.
RCheck the tire for foreign objects.
RCheck 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 and
malfunction, 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 gage 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 pres-
sure can be checked in the on-board com-
puter.
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:
Rif the vehicle has been parked with the tires
out of direct sunlight for at least three
hours and
Rif 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 ba r/
1. 5psi) . 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. T
his is normal. Do not reduce the tire
pressure to the value specified for cold tires.
The tire pressure would otherwise be too low.
Observe the recommended tire pressures for
cold tires:
Ron the Tire and Loading Information placard
on the B-pillar on the driver's side
Rin the tire pressure table on the inside of the
fuel filler flap
Tire pressure367
Wheels and tires
Z
Page 370 of 410

Underinflated or overinflated tires
Underinflated tires
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:
Roverheat, leading to tire defects
Radversely affect handling
Rwear excessively and/or unevenly
Rhave an adverse effect on fuel consumption
Overinflated tires
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:
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 rec-
ommended tire pressure for your vehicle
when adjusting the tire pressure
(
Ypage 365).
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 365).
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 (
Ypage 168)
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 gage securely onto
the valve.
368Tire pressure
Wheels and tires
Page 371 of 410

XRead thetire pressur eand compar eit to
th erecommended value on th eTir eand
Loadin gInformation placard or th etire
pressur etable (
Ypage 365).
XIf thetire pressur eis to olow, increase th e
tire pressur eto th erecommended value .
XIf thetire pressur eis to ohigh ,release air.
To do so, press down th emetal pin in th e
valve, usin gth etip of apen for example.
The nchec kth etire pressur eagain usin g
th etire pressur echecker.
XScrew th evalv ecap onto th evalve.
XRepeat these steps for th eother tires .
Tire pressure monitor
Genera lnotes
If atire pressur emonitor is installed, th evehi-
cle's wheels hav esensor sthat monitor th e
tire pressures in all fou rtires .The tire pres-
sur emonitor warn syou if th epressur edrops
in on eor mor eof th etires .The tire pressur e
monitor only function sif th ecorrespondin g
sensor sare installed in all wheels.
Information on tire pressures is displayed in
th emultifunction display. Afte r afew minute s
of driving, th ecurren ttire pressur eof eac h
tire is shown in th eServic e
menuof th emul-
tifunction display, see illustration (example).
Fo rinformation on th emessage display, refer
to th e"Checking th etire pressur eelectroni-
cally" section (
Ypage 370).
Important safety notes
GWARNING
Eac htire, includin gth espar e(if provided),
should be checke dat leas tonce every tw o
week swhen cold and inflated to th epressur e
recommended by th evehicl emanufacturer
on th eTir eand Loadin gInformation placard
on th edriver's doo rB-pillar or th etire pres-
sur elabel on th einside of th efuel filler flap .If
your vehicl ehas tires of adifferen tsiz ethan
th esiz eindicate don th eTir eand Loadin g
Information placard or, if available, th etire
pressur elabel ,you should determin eth e
proper tire pressur efor those tires .
As an added safet yfeature, your vehicl ehas
been equipped wit h atire pressur emonitoring
system (TPMS) that illuminate s alow tire pres-
sur etelltale when on eor mor eof your tires
are significantly underinflated. Accordingly,
when th elow tire pressur etelltale lights up,
you should stop and chec kyour tires as soo n
as possible, and inflat ethem to th eproper
pressure. Drivin gon asignificantly underin-
flated tire causes th etire to overheat and can
lead to tire failure.
Underinflation also reduce sfuel efficiency
and tire tread life ,and may affec tth evehicle's
handlin gand stopping ability. Pleas enote that
th eTPM Sis no t a
substitu
t efor proper tire
maintenance ,and it is th edriver's responsi-
bilit yto maintai ncorrec ttire pressure, eve nif
underinflation has no treached th elevel to
trigge rillumination of th eTPM Slow tire pres-
sur etelltale.
Your vehicl ehas also been equipped wit h a
TPM Smalfunction indicato rto indicate when
th esystem is no toperating properly. The
TPM Smalfunction indicato ris combine dwit h
th elow tire pressur etelltale. Whe nth esys-
te m detects amalfunction ,th ewarnin glamp
will flas hfor approximately aminute and then
remain continuousl yilluminated. This
sequence will be repeated every time th evehi-
cle is started as lon gas th emalfunction
exists. Whe nth emalfunction indicato ris illu-
Tire pressure36 9
Wheels and tires
Z
Page 372 of 410

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 365). 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
(
Ypage 371). 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
(
Ypage 365).
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 pressure loss or a malfunction. Whether
the warning lamp flashes or lights up indi-
cates whether a tire pressure is too low or the
tire pressure monitor is ma
lfunctioning:
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 279).
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 gage.
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 gage 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 151).
XUse ò on the steering wheel to call up
the list of menus.
XPress 9or: on the steering wheel
to select the Service
menu.
XPress theabutton.
370Tire pressure
Wheels and tires
Page 373 of 410

XPress9or: to select Tire Pres‐
sure.
XPress the abutton.
The current tire pressure of each tire is
shown in the multifunction display.
If the vehicle was parked for longer than
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 Activemessage is shown instead
of the tire pressure display. The tire pressures are already being monitored.
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 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.
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 279).
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 365).
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 365).
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.
XUse ò on the steering wheel to call up
the list of menus.
XPress 9or: on the steering wheel
to select the Service
menu.
XPress theabutton.
XPress 9or: to select Tire Pres‐
sure.
XPress the abutton.
The current tire pressure for each wheel or
the Tire
pressurewillbedisplayed
afterdrivingafewminutesmessage
Tire pressure371
Wheels and tires
Z
Page 374 of 410

will be displayed in the multifunction dis-
play.
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
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 numberof 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.
The maximum gross axle weight rating is
the 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
372Loading the vehicle
Wheels and tires
Page 375 of 410

Maximum permissible gross vehicle
weight rating
XSpecification 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 Information
placard.
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".
XStep 1: Locate the statement "The com-
bined weight of occupants and cargo
should never exceed XXX kg or XXX lbs." on
your vehicle’s Tire and Loading Information
placard.
XStep 2: Determine the combined weight of
the driver and passengers that will be riding
in your vehicle.
XStep 3: Subtract the combined weight of
the driver and passengers from XXX kilo-
grams or XXX lbs.
XStep 4: The resulting figure equals the
available amount of cargo and luggage load capacity. For example, if the "XXX" amount
equals 1400 lbs and there will be five
150-lb passengers in your vehicle, the
amount of available cargo and luggage load
capacity is 650 lbs (1400 - 750 (5 x 150) =
650 lbs).
XStep 5: Determine the combined weight of
luggage and cargo being loaded on the
vehicle. That weight may not safely exceed the available cargo and luggage load capa-
city calculated in step 4.
Loading the vehicle373
Wheels and tires
Z
Page 376 of 410

Example: steps 1 to 3
The following table shows examples on how to calculate total and cargo load capacities with
varying seating configurations and number and size of occupants. The following examples use
a load limit of 1500 lbs (680 kg).This is for illustration purposes only. Make sure you are
using the actual load limit for your vehicle stated on your vehicle's Tire and Loading Information
placard (
Ypage 372).
The greater the combined weight of the occupants, the lower the maximum luggage load.
Example 1
Step 1
RCombined maximum weight of occupants and load (data from the Tire and Loading Infor-
mation placard): 1500 lbs (680 kg)
Step 2
RNumber of people in the vehicle (driver and occupants): 5
RDistribution of the occupants
-Front: 2
-Rear: 3
RWeight of the occupants
-Occupant 1: 150 lbs (68 kg)
-Occupant 2: 18 0 lbs (82 kg)
-Occupant 3: 160 lbs (73 kg)
-Occupant 4: 140 lbs (63 kg)
-Occupant 5: 120 lbs (54 kg)
RTotal weight of all occupants: 750 lbs (340kg )
Ste p 3
RPerm issible load (maximum gross vehicle weight rating from the Tire and Loading Informa-
tion placard minus the gross weight of all occupants):
1500 lbs (680 kg) Ò750 lbs (340 kg) = 750 lbs (340 kg)
Example 2
Step 1
RCombined maximum weight of occupants and load (data from the Tire and Loading Infor-
mation placard): 1500 lbs (680kg )
Ste p 2
RNumber of peop le in the vehicle (driver and occupants): 3
RDistribution of the occupants
-Front: 1
-Rear: 2
374Loading the vehicle
Wheels and tires