Checking the tire pressures
Important safety notes Observe the notes on tire pressure
(Y page 322).
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 filler
flap (Y page 159)
R in the "Tire pressure" section
Checking tire pressures manually To determine and set the correct tire pres-
sure, proceed as follows:
X Remove 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 (Y page 322).
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
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 in the multifunction display in the Serv.
Serv.
menu, by the Run RunFlat
Flat Indicator
Indicator Active
Active
Press 'OK' to Restart
Press 'OK' to Restart message. Further
information on displaying this message can
be found under "Restarting the tire pressure
loss warning system" (Y page 326).
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 (Y page 322).
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 by
the 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 are driving with a heavy load (in the
vehicle or on the roof). Tire pressure
325Wheels and tires Z
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 pressure is set, these incorrect values
will be monitored.
X Also observe the notes in the section on tire
pressures (Y page 322).
X Make sure that the SmartKey is in position
2 in the ignition lock (Y page 141) .
X Press =or; on the steering wheel
to select the Serv.
Serv. menu.
X Press the 9or: button to select
Tire Pressure
Tire Pressure .
X Press the abutton.
The Run Flat Indicator active Run Flat Indicator active
Restart
Restart with
withOK
OKmessage appears in the
multifunction display.
If you wish to confirm the restart: X Press the abutton.
The Tire Pressure Now OK?
Tire Pressure Now OK? message
appears in the multifunction display.
X Press the 9or: button to select
Yes
Yes.
X Press the abutton.
The Run Flat Indicator restarted
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?
Tire Pressure Now OK? message
appears, press the 9or: button to
select Cancel 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 Serv.
Serv. menu of the multi-
function display, see illustration (example). For information on the message display, refer
to the "Checking the tire pressure electroni-
cally" section (Y page 328).
Important safety notes G
WARNING
Each tire, including the spare (if provided),
should be checked at least once every two 326
Tire pressureWheels and tires
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 that the 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 with
the 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
(Y page 322). 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 328). 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 322).
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. Tire pressure
327Wheels and tires Z
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-
uation on the Tire and Loading Information
placard on the driver's side
B-pillar (Y page 322).
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 159).
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 (Y page 141).
X Press =or; on the steering wheel
to select the Serv. Serv.menu.
X Press the 9or: button to select
Tire Pressure
Tire Pressure.
X Press the abutton.
The multifunction display shows the cur-
rent tire pressure for each tire or the Tire
Tire
pressure will be displayed after
pressure will be displayed after
driving a few minutes driving a few minutes message.
X Press the :button.
The multifunction display shows the Use
Use
current
current pressures
pressures as
asnew
new reference
reference
values
values message.
If you wish to confirm the restart: X Press the abutton.
The Tire Press. Monitor Restarted
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 Country Radio type approval number
USA FCC ID: MRXMW2433A
FCC ID: MRXGG4
FCC ID: MRXMC34MA4
Canada IC: 2546A-MW2433A
IC: 2546A-GG4
IC: 2546A-MC34MA4
Loading the vehicle
Instruction labels for tires and loads
G
WARNING
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 Loading the vehicle
329Wheels and tires Z
Step 3
Example 1 Example 2 Example 3
Permissible load
(maximum gross vehi-
cle weight rating from
the Tire and Loading
Information placard
minus the gross
weight of all occu-
pants) 1500 lbs (680 kg)
Ò
750 lbs (340 kg) =
750 lbs (340 kg) 1500 lbs (680 kg)
Ò
540 lbs (245 kg)
=960 lbs (435 kg) 1500 lbs (680 kg)
Ò
150 lbs (68 kg) =
1350 lbs (612 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
(Y page 329).
Permissible Gross Vehicle Weight Rating
(GVWR): the gross weight of the vehicle, all
passengers, load and trailer load/noseweight (if applicable) must not exceed the permissi-
ble 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, cargo, and full trailer load if applicable) 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: :tread wear 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.
Quality grades can be found, where applica-
ble, on the tire sidewall between tread shoul-
der and maximum section width. All about wheels and tires
333Wheels and tires Z
Example:
R Treadwear grade: 200
R Traction grade: AA
R Temperature grade: A
All passenger car tires must conform to the
statutory safety requirements in addition to
these grades.
i The 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.
Traction G
WARNING
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 wet pavement as
measured under controlled conditions on
specified government test surfaces of asphalt
and concrete. A tire marked C may have poor
traction performance. 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 of ãin (4 mm) on all four winter
tires. Observe the legally required minimum
tire tread depth (Y page 319). Winter tires can
reduce the braking distance on snow-covered surfaces in comparison with summer tires.
The braking distance is still much further thanon surfaces that are not icy or covered with
snow. Take appropriate care when driving.
Further information on winter tires (M+S
tires) (Y page 320).
Temperature G
WARNING
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, representing the tire's resistance to
the generation of heat and its ability to dissi- pate heat when tested under controlled con-
ditions 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 temperature
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. 334
All about
wheels and tiresWheels and tires
All-weather tires and winter tires
Index Speed rating
Q M+S
1 up to 100 mph (160 km/h)
T M+S
1 up to 118 mph (190 km/h)
H M+S
1 up to 130 mph (210 km/h)
V M+S
1 up to 149 mph (240 km/h)
i
Not all tires with the M+S marking provide
the driving characteristics of winter tires. In
addition to the M+S marking, winter tires
also have the isnowflake symbol on
the tire wall. Tires with this marking fulfill
the requirements of the Rubber Manufac-
turers Association (RMA) and the Rubber
Association of Canada (RAC) regarding the
tire traction on snow. They have been espe- cially developed for driving on snow.
An electronic speed limiter prevents your
vehicle from exceeding a speed of 130 mph
(210 km/ h).
The speed rating of tires mounted at the fac-
tory may be higher than the maximum speed
that the electronic speed limiter permits.
Make sure that your tires have the required
speed rating, e.g. when buying new tires. The required speed rating for your vehicle can be
found in the "Tires" section (Y page 345).
Further information about reading tire data
can be obtained from any qualified specialist workshop. Load index In addition to the load-bearing index, load
index
:may be imprinted after the letters
that identify speed rating on the sidewall of
the tire. Speed rating (Y page 335).
R If no specification is given: no text (as in the
example above), represents a standard
load (SL) tire
R XL or Extra Load: represents a reinforced
tire
R Light Load: represents a light load tire
R C, D, E: represents a load range that
depends on the maximum load that the tire
can carry at a certain pressure
i Tire data is vehicle-specific and may devi-
ate from the data in the example.
Maximum load rating Maximum tire load
:is the maximum per-
missible weight for which the tire is approved.
Do not overload the tires by exceeding the
specified load limit. The maximum permissi-
1 Or M+S ifor winter tires. All about wheels and tires
337Wheels and tires Z
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
(Y page 300) contains information and notes
on how to deal with a flat tire. Information on driving with MOExtended tires in the event of
a flat tire can be found under "MOExtended
tires (tires with run-flat characteristics"
(Y page 301). Rotating the wheels
G
WARNING
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 loca-
ted in the wheel.
Tire-mounting tools should not be used
near the valve. This could damage the elec- tronic components.
Only have tires changed at a qualified spe-cialist workshop.
Observe the instructions and safety notes in
the "Changing a wheel" section (Y page 341).
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.
If your vehicle's tire configuration allows, you can rotate the wheels according to the inter-
vals 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), or earlier if tire wear requires.
Ensure the direction of rotation is maintained.
Clean the contact surfaces of the wheel and
the brake disc thoroughly every time a wheel
is rotated. Check the tire pressure and, if nec- essary, restart the tire pressure loss warning
system or the tire pressure monitor. Direction of rotation
Tires with a specified direction of rotation
have additional benefits, e.g. if there is a risk
of hydroplaning. These advantages can only
be gained if the tires are installed correspond- ing to the direction of rotation.
An arrow on the sidewall of the tire indicates
its correct direction of rotation. Storing wheels
Store wheels that are not being used in a cool,
dry and preferably dark place. Protect the
tires from oil, grease, gasoline and diesel. Mounting a wheel
Preparing the vehicle X
Stop the vehicle on solid, non-slippery and
level ground.
X Apply the electric parking brake manually.
X Bring the front wheels into the straight-
ahead position.
X Shift the transmission to position P.
X Switch off the engine. Changing a wheel
341Wheels and tires Z