Information on air pressure for the tires on
yourvehicle can be found:
Ron the vehicle's Tire and Loading
Information placard on the B-pillar
Ron the tire pressure label on the fuel filler
flap
Rin the "Tire pressure information" section
Checking tire pressures manually
To determine and set the correct tire
pressure, 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 with
the recommended value on the Tire and
Loading Information placard on the
B-pillar on the driver's side of your vehicle.
XIf necessary, increase the tire pressure to
the recommended value (Ypage 316).
XIf the tire pressure is too high, release air
by pressing down the metal pin in the valve
using the tip of a pen, for example. Then,
checkthe tire pressure again using the tire
pressure gauge.
XScrew the valve cap onto the valve.
XRepeatthese steps for the other tires.
Tire pressure loss warning system
(Canada only)
General notes
While the vehicle is in motion, the tire
pressure 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 appearinthe multifunction
display.
You can recognize the tire pressure loss
warning by theRun Flat Indicator
Active Press 'OK' to Restartmessage
which appears in theServicemenu of the
multifunction display. Further information on
the message display can be found under
"Restarting the tire pressure loss warning
system" (Ypage 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 316).
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:
Rsnow chains are mounted on your vehicle's
tires.
Rroad conditions are wintry.
Ryou are driving on sand or gravel.
Ryou adopt a very sporty driving style
(cornering at high speeds or driving with
high rates of acceleration).
Ryou are driving with a heavy load (in the
vehicle or on the roof).
Restarting the tire pressure loss
warning system
Restart the tire pressure loss warning system
if you have:
Rchanged the tire pressure
Rchanged the wheels or tires
Rmounted new wheels or tires
Tire pressure319
Wheels and tires
Z
XBefore restarting, make sure that the tire
pressures are set properly on all fourtires
for the respective operating conditions.
The recommended tire pressures can be
found on the Tire and Loading Information
placard on the B-pillar on the driver's side
or the tire pressure table on the fuel filler
flap. The tire pressure loss warning system
can only give reliable warnings if you have
set the correct tirepressure. If an incorrect
tire pressure is set, these incorrect values
will be monitored.
XAlso observe the notes in the section on tire
pressures (Ypage 316).
XMake sure that the SmartKey is in position
2in the ignitionlock (Ypage 137).
XPress or on the steering wheel
to select theServicemenu.
XPress the or button to select
Tire Pressure.
XPress the button.
TheRun Flat Indicator Active
Press 'OK' to Restartmessage
appears in the multifunction display.
If you wish to confirm the restart:
XPress the button.
TheTire Pressure Now OK?message
appears in the multifunction display.
XPress the or button to select
Yes.
XPress the button.
TheRun Flat Indicator Restarted
message appears in the multifunction
display.
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:
XPress the button.
or
XWhen theTire Pressure Now OK?
message appears, press the
or button to selectCancel.
XPress the button.
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
vehicle's wheels have sensors that monitor
the tire pressures in all four tires. The tire
pressure monitor warns you if the pressure
drops in one or more of the tires. The tire
pressure monitor only functions if the correct
sensors are installed on 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 shownintheServicemenu of the
multifunction display. For further information
on displaying this message, refer to the
"Checking the tire pressure electronically"
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
recommended 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
Information 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
pressure telltale when one or more of your
320Tire pressure
Wheels and tires
tires are significantly underinflated.
Accordingly, when the low tire pressure
telltale illuminates, you shouldstop and check
your tires as soonas possible, and inflate
them to the proper pressure. Driving on a
significantly underinflated 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 responsibility to maintain correct tire
pressure, even if underinflation 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
remain continuously illuminated. This
sequence will be repeated every time the
vehicle 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
malfunctions 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 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 316). Note that the correct tire
pressure 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 adjusting the pressure of the
cold tires (Ypage 322). The current
pressures are saved as new reference values.
As a result, a warning message will appearif
the tire pressure 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 316).
The tire pressure monitor is not able to warn
you of a sudden loss of pressure, e.g.ifthe
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
warning lamp in the instrument cluster for
indicating a pressure loss or malfunction.
Whether the warning lamp flashes or lights up
indicates 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
significantly 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.
iIn addition to the warning lamp, a
message appears in the multifunction
display.
Further information can be found on
(Ypage 234).
If the tire pressure monitor is malfunctioning,
it may take more than ten minutes for the tire
pressure warning lamp to inform you of 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.
Tire pressure321
Wheels and tires
Z
XSet the tire pressure to the value
recommended for the corresponding
driving situation on the Tire and Loading
Information placard on the driver's side
B-pillar (Ypage 316).
Additional tire pressure values for different
loads can also be found on the tire pressure
table on the inside of the fuel fillerflap
(Ypage 316).
XMake sure that the tire pressure is correct
on all four wheels.
XMake sure that the SmartKey is in position
2in the ignition lock.
XPress the or button on the
steering wheel to selecttheService
menu.
XPress the or button to select
Tire Pressure.
XPress the button.
The multifunction display shows the
current tire pressure for the individual tires
or theTire pressure will be
displayed after driving a few
minutesmessage.
XPress the button.
TheUse Current Pressures as New
Reference Valuesmessage appears in
the multifunction display.
If you wish to confirm the restart:
XPress the button.
TheTire Press. Monitor Restarted
message appears in the multifunction
display.
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.
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.
B-pillar, driver's side
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
permissible vehicle load. It also contains
details of the tire sizes and
corresponding pressures 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
occupants, 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 tires
Z
Uniform Tire Quality Grading
Standards
Overview of Tire Quality Grading
Standards
Uniform Tire Quality Grading Standards are
U.S. government specifications. Their
purpose is to provide drivers with uniform
reliable information on tire performance data.
Tire manufacturers have to grade tires using
three performance factors: tread wear ,
tire traction , and heat resistance ".
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.
All passenger car tires must conform to the
statutory safety requirements in addition to
these grades.
Where applicable, the tire grading
information can be found on the tire sidewall
between the tread shoulder and maximum
tire width.
iThe actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
For example:
TreadwearTractionTemperature
200AAA
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,
however, and may depart significantly from
the norm, due to variations in driving habits,
service practices and differences in road
characteristics and climateconditions.
Traction
GWARNING
The traction grade assigned to this tire is
based on straight-ahead braking traction
tests, and does not include acceleration,
cornering, hydroplaning, or peak traction
characteristics.
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.Atire 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
surfaces.
You should pay special attention to road
conditions when temperatures are around
the freezing point.
Mercedes-Benz recommends a minimum
tread depth of \nin(4mm) for all four winter
tires (Ypage 314) to maintainnormal driving
characteristics in winter. Winter tires can
reduce the braking distance on snow-covered
surfaces in comparison with summer tires.
Stopping distance, however, is still
considerably greater than when the road is
328Uniform Tire Quality Grading Standards
Wheels and tires
not covered with ice or snow. Take
appropriate care when driving.
!Avoid wheelspin. This can lead to damage
to the drive train.
Temperature
GWARNING
The temperature grade for this tire is
established for a tire thatis properly inflated
and not overloaded.Excessive speed,
underinflation, or excessive loading, either
separately or in combination, can cause
excessive heatbuild-up and possible tire
failure.
The temperature grades areA(the highest),
B, and C. These represent the tire's
resistance to the generationofheat and its
ability to dissipate 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 temperature can lead to sudden
tire failure. The gradeCcorresponds 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 of tire labeling
The following markings are on the tire in additionto the tire name (sales designation) and themanufacturer's name:
Uniform tire Quality Grading Standard
(Ypage 333)
DOT, Tire Identification Number
(Ypage 332)
"Maximum tire load (Ypage 327)
!Maximum tire pressure (Ypage 318)
Manufacturer
Tire material (Ypage 333)
Tire size designation, load-bearing
capacity and speed index (Ypage 330)
Load index (Ypage 332)
Tire name
iTire data is vehicle-specific and may
deviate from the data in the example.
Tire labeling329
Wheels and tires
Z
adapt your driving style to the traffic
conditions.
Summer tires
IndexSpeed rating
Qup to 100mph (160 km/h)
Rup to 106mph (170 km/h)
Sup to 112mph (180 km/h)
Tup to 118mph (190 km/h)
Hup to 130mph (210 km/h)
Vup to 149mph (240 km/h)
Wup to 168mph (270 km/h)
Yup to 186mph (300 km/h)
ZR...Yup to 186mph (300 km/h)
ZR...(..Y)over 186mph (300 km/h)
ZRover 149mph (240 km/h)
ROptionally, tires with a maximum speed of
over149 mph(240km/h) may have "ZR" in
the size description, depending on the
manufacturer (e.g. 245/40 ZR 18).
The service specifications consist of load
bearing index and speed rating .
RIf the size description of yourtire includes
"ZR" and there are no service
specifications, ask the tire manufacturer in
order to find out the maximum speed.
If a service specification is available, the
maximum speed is limited according to the
speed rating in the service specification.
Example: 245/40 ZR 18 97 Y. In this
example, "97 Y" is the service specification.
The letter "Y" represents the speed rating
and the maximum speed of the tire is
limited to 186 mph (300km/h).
RThe size description for all tires with
maximum speeds of over 186mph
(300km/h) must include "ZR",andthe
service specification must be given in
brackets. Example: 275/40 ZR 18 (99 Y).
The speed rating "(Y)" indicates that the
maximum speed of the tire is over 186mph
(300km/h). Ask the tire manufacturer
about the maximum speed.
All-weather tires and winter tires
IndexSpeed rating
Q M+S5up to 100mph (160 km/h)
T M+S5up to 118mph (190 km/h)
H M+S5up to 130mph (210 km/h)
V M+S5up to 149mph (240 km/h)
iNot all tires with the M+S marking provide
the driving characteristics of winter tires.
Winter tires have, in additionto the M+S
identification, the snow flake symbol
on the tire sidewall. Tires with this marking
fulfill the requirements of the Rubber
Manufacturers Association (RMA) and the
Rubber Association of Canada (RAC)
regarding the tire traction on snow. They
have been especially developed for driving
on snow.
An electronic speed limiter prevents your
vehicle from exceeding a speed of 130mph
(210km/h).
The speed rating of tires mounted at the
factory 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 (Ypage 340).
Further information about reading tire data
can be obtained from any qualified specialist
workshop.
5Or M+S for winter tires.
Tire labeling331
Wheels and tires
Z
GAWR (Gross Axle Weight Rating)
The GAWR is the maximumgross axle weight
rating. The actual load on an axle must never
exceed the gross axle weight rating. The
gross axle weight rating can be found on the
vehicle identification plate on the B-pillar on
the driver's side.
Speed rating
The speed rating is part of the tire
identification. It specifies the speed range for
which the tire is approved.
GVW (Gross Vehicle Weight)
The gross vehicle weight includes the weight
of the vehicle including fuel, tools, the spare
wheel, accessories installed, occupants,
luggage and the drawbar noseweight, if
applicable.The gross vehicle weight must not
exceed the gross vehicle weight rating GVWR
as specified on the vehicle identification plate
on the B-pillar on the driver's side.
GVWR (Gross Vehicle Weight Rating)
The GVWR is the maximum permissible gross
weight of a fully loaded vehicle (the weight of
the vehicle including all accessories,
occupants, fuel, luggage and the drawbar
noseweight, if applicable). The gross vehicle
weight rating is specified on the vehicle
identification plate on the B-pillar on the
driver's side.
Maximum loaded vehicle weight
The maximum weight is the sum of:
Rthe curb weight of the vehicle
Rthe weight of the accessories
Rthe load limit
Rthe weight of the factory installed optional
equipment
Kilopascal (kPa)
Metric unit for tire pressure. 6.9 kPa
corresponds to 1 psi. Another unit for tire
pressure is bar. 100 kilopascal (kPa) is the
equivalent of1bar.
Load index
In addition to the load-bearing index, the load
index may also be imprinted on the sidewall
of the tire. This specifiesthe load-bearing
capacity more precisely.
Curb weight
The weight of a vehicle with standard
equipment including the maximum capacity
of fuel, oil and coolant. It also includes the air-
conditioning system and optional equipment
if these are installed in the vehicle, but does
not include passengers or luggage.
Maximum load rating
The maximum load rating in kilograms or
pounds is the maximum weight for which a
tire is approved.
Maximum permissible tire pressure
Maximum permissible tire pressure for one
tire.
Maximum load on one tire
Maximum load on one tire. This is calculated
by dividing the maximum axle load of one axle
by two.
PSI (pounds per square inch)
Astandard unitofmeasure for tire pressure.
334Definition of terms for tires and loading
Wheels and tires