Page 577 of 614

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 571).
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 Serv.
menu of the multi-
function display.
Example :curren ttir epressur edisplay
For information on the message display, refer
to the "Checking the tire pressure electroni-
cally" section (
Ypage 577).
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 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 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
reduces fuel efficiency and tire tread life, and
may 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 unde rinf
lation has not
reached the level to trigger illumination of the
TPMS low tire pressure telltale.
USA only:
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
Tire pressure575
Wheels and tires
Z
Page 578 of 614

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 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 mounting 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 wheels
allow 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
(
Ypage 571). 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 577). 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 571).
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 clu
ster 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 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 264).
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.
576Tire pressure
Wheels and tires
Page 579 of 614

Checking the tire pressure electroni-
cally
XMake sure that the SmartKey is in position2 in the ignition lock (
Ypage 151).
XPress the =or; button on the steer-
ing wheel to select the Serv.
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.
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.
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 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
(
Ypage 264).
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 displayed
for the correct 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 571).
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 571).
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 Serv.
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
Tire pressure577
Wheels and tires
Z
Page 580 of 614

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
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
578Loading the vehicle
Wheels and tires
Page 581 of 614

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 vehicle579
Wheels and tires
Z
Page 582 of 614

Example: steps 1 to 3
The following table shows examples on how
to calculate total and cargo load capacities
with varying seating configurations and num-
ber 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 578).
The greater the combined weight of the occu-
pants, the lower the maximum luggage load.
Step 1
Example 1Example 2
Combined
maximum
weight of
occupants
and cargo
(data from the
Tire and Load-
ing Informa-
tion placard)1500 lbs
(680 kg)1500 lbs
(680 kg)
Step 2
Example 1Example 2
Number of
people in the
vehicle (driver
and occu-
pants)12
Weight of the
occupantsOccu-
pant 1:
175 lbs
(80 kg)Occu-
pant 1:
175 lbs
(80 kg)
Occu-
pant 2:
195 lbs
(88 kg)
Gross weight
of all occu-
pants175 lbs
(80 kg)370 lbs
(168 kg)
Step 3
Example 1Example 2
Permissible
load (maxi-
mum gross
vehicle weight
rating from
the Tire and
Loading Infor-
mation plac-
ard minus the
gross weight
of all occu-
pants)1500 lbs
(680 kg) Ò
175 lbs
(80 kg) =
1325 lbs
(600 kg)1500 lbs
(680 kg) Ò
370 lbs
(168 kg) =
1130 lbs
(512 kg)
Vehicle identification plate
Even if you have calculated the total cargo
carefully, you should still make sure that the
gross vehicle weight rating and the gross axle
weight rating are not exceeded. Details can
be found on the vehicle identification plate on
the B-pillar on the driver's side of the vehicle
(
Ypage 578).
580Loading the vehicle
Wheels and tires
Page 583 of 614

Permissible gross vehicle weight:the
gross weight of the vehicle, all passengers
and the load must not exceed the permissible
gross vehicle weight.
Gross Axle Weight Rating (GAWR): the
maximum permissible weight that can be car-
ried by one axle (front or rear axle).
To ensure that your vehicle does not exceed
the maximum permissible values (gross vehi-
cle weight and maximum gross axle weight
rating), have your loaded vehicle (including
driver, occupants and the load) weighed on a
suitable vehicle weighbridge.
All about wheels and tires
Uniform Tire Quality Grading Stand-
ards
Overview of Tire Quality Grading Stand-
ards
Uniform Tire Quality Grading Standards are
U.S. government specifications. Their pur-
pose is to provide drivers with uniform relia-
ble information on tire performance data. Tire
manufacturers have to grade tires using three
performance factors: treadwear grade :,
traction grade ;and temperature grade =.
These regulations do not apply to Canada.
Nevertheless, all tires sold in North America
are provided with the corresponding quality
grading markings on the sidewall of the tire.
Where applicable, the tire grading informa-
tion can be found on the tire sidewall between
the tread shoulder and maximum tire width. Example:
RTreadwear grade:
200
RTraction grade:AA
RTemperature grade: A
All passenger car tires must conform to the
statutory safety requirements in addition to
these grades.
iThe actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
Treadwear
The treadwear grade is a comparative rating
based on the wear rate of the tire when tested
under controlled conditions on a specified
U.S. government course. For example, a tire
graded 150 would wear one and one-half
times as well on the government course as a
tire graded 100.
The relative performance of tires depends
upon the actual conditions of their use, how-
ever, and may depart significantly from the
norm, due to variations in driving habits, ser-
vice practices and differences in road char-
acteristics and climate conditions.
Traction
GWARNING
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration, cor-
nering, hydroplaning, or peak traction char-
acteristics.
!Avoid wheelspin. This can lead to damage
to the drive train.
The traction grades, from highest to lowest,
are AA, A, B, and C. Those grades represent
the tire's ability to stop on a wet surface as
measured under controlled conditions on
specified government test surfaces of asphalt
and concrete. A tire marked C may have poor
traction performance.
All about wheels and tires581
Wheels and tires
Z
Page 584 of 614

The safe speed on a wet, snow covered or icy
road is always lower than on dry road surfa-
ces.
You should pay special attention to road con-
ditions when temperatures are around freez-
ing point.
Mercedes-Benz recommends a minimum
tread depth ofãin (4 mm) on all four winter
tires. Observe the legally required minimum
tire tread depth (
Ypage 569). Winter tires can
reduce the braking distance on snow-covered
surfaces in comparison with summer tires.
The braking distance is still much further than
on surfaces that are not icy or covered with
snow. Take appropriate care when driving.
Further information on winter tires (M+S
tires) (
Ypage 570).
Temperature
GWARNING
The temperature grade for this tire is estab-
lished for a tire that is properly inflated and
not overloaded. Excessive speed, underinfla-
tion, or excessive loading, either separately or
in combination, can cause excessive heat
build-up and possible tire failure.
The temperature grades are A (the highest), B,
and C. These represent the tire's resistance
to the generation of heat and its ability to dis-
sipate heat when tested under controlled
conditions on a specified indoor laboratory
test wheel. Sustained high temperature can
cause the material of the tire to degenerate
and reduce tire life, and excessive tempera-
ture can lead to sudden tire failure. The grade
C corresponds to a level of performance
which all passenger car tires must meet under
the Federal Motor Vehicle Safety Standard
No. 109. Grades B and A represent higher
levels of performance on the laboratory test
wheel than the minimum required by law.
Tire labeling
Overview
:Uniform Tire Quality Grading Standard
(
Ypage 586)
;DOT, Tire Identification Number
(
Ypage 585)
=Maximum tire load (Ypage 585)
?Maximum tire pressure (Ypage 574)
AManufacturer
BTire material (Ypage 586)
CTire size designation, load-bearing capa-
city and speed index (
Ypage 582)
DLoad index (Ypage 585)
ETire name
The markings described above are on the tire
in addition to the tire name (sales designa-
tion) and the manufacturer's name.
iTire data is vehicle-specific and may devi-
ate from the data in the example.
Tire size designation, load-bearing
capacity and speed rating
GWARNING
Exceeding the stated tire load-bearing capa-
city and the approved maximum speed could
lead to tire damage or the tire bursting. There is a risk of accident.
582All about wheels and tires
Wheels and tires