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
Therefore, only use tire types and sizes
approved for your vehicle model. Observe the
tire load rating and speed rating required for
your vehicle.
General:depending on the manufacturer's
standards, the size imprinted in the tire wall
may not contain any letters or may contain
one letter that precedes the size description.
If there is no letter preceding the size descrip- tion (as shown above): these are passenger
vehicle tires according to European manufac-
turing standards.
If "P" precedes the size description: these are
passenger vehicle tires according to U.S.
manufacturing standards.
If "LT" precedes the size description: these
are light truck tires according to U.S. manu-
facturing standards.
If "T" precedes the size description: compact
emergency wheels with high tire pressure
that are only designed for temporary use in an
emergency.
Tire width: tire width:shows the nominal
tire width in millimeters.
Height-width ratio: aspect ratio;is the
size ratio between the tire height and tire
width and is shown in percent. The aspect
ratio is calculated by dividing the tire width by the tire height.
Tire code: tire code=specifies the tire type.
"R" represents radial tires; "D" represents
diagonal tires; "B" represents diagonal radial
tires. Optionally, tires with a maximum speed of
over 149 mph (240 km/h) may have "ZR" in
the size description, depending on the man-
ufacturer (e.g. 245/40 ZR 18).
Rim diameter:
rim diameter?is the diam-
eter of the bead seat, not the diameter of the
rim flange. The rim diameter is specified in
inches (in).
Load-bearing index: load-bearing indexA
is a numerical code that specifies the maxi-
mum load-bearing capacity of a tire.
Do not overload the tires by exceeding the
specified load limit. The maximum permissi-
ble load can be found on the vehicle's Tire and
Loading Information placard on the B-pillar on
the driver's side (Ypage 372).
Example:
Load-bearing index 91 indicates a maximum
load of 1,356 lb (615 kg) that the tires can
bear. For further information on the maximum tire load in kilograms and lbs, see
(
Ypage 380).
For further information on the load bearing
index, see "Load index" (
Ypage 379).
Speed rating: speed ratingBspecifies the
approved maximum speed of the tire.
iTire data is vehicle-specific and may devi-
ate from the data in t
he example.
Regardless of the speed rating, always
observe the speed limits. Drive carefully and
adapt your driving style to the traffic condi-
tions.
Summer tires
IndexSpeed rating
Qup to 100 mph (160 km/h)
Rup to 106 mph (170 km/h)
Sup to 112 mph (180 km/h)
Tup to 118 mph (190 km/h)
Hup to 130 mph (210 km/h)
Vup to 149 mph (240 km/h)
378All about wheels and tires
Wheels and tires
ter that identifies the speed rating
(
Ypage 377).
RIf no specification is given: no text (as in the
example above), represents a standard
load (SL) tire
RXL or Extra Load: represents a reinforced
tire
RLight Load: represents a light load tire
RC, D, E: represents a load range that
depends on the maximum load that the tire
can carry at a certain pressure
iTire 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-
ble load can be found on the vehicle's Tire and
Loading Information placard on the B-pillar on the driver's side (
Ypage 372).
iThe actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
DOT, Tire Identification Number (TIN)
US tire regulations stipulate that every tire
manufacturer or retreader must imprint a TIN in or on the sidewall of each tire produced.
The TIN is a unique identification number. The
TIN enables the tire manufacturers or retread-
ers to inform purchasers of recalls and other
safety-relevant matters. It makes it possible
for the purchaser to easily identify the affec-
ted tires.
The TIN is made up of manufacturer identifi-
cation code ;, tire size=, tire type code ?
and manufacturing date A.
DOT (Department of Transportation): tire
symbol :marks that the tire complies with
the requirements of the U.S. Department of
Transportation.
Manufacturer identification code: manu-
facturer identification code ;provides
details on the tire manufacturer. New tires
have a code with two symbols. Retreaded
tires have a code with four symbols.
Tire size: identifier=describes the tire size.
Tire type code: tire type code?can be used
by the manufacturer as a code to describe
specific characteristics of the tire.
Date of manufacture: date of manufacture
A provides information about the age of a
tire. The first and second positions represent the week of manufacture, starting with "01"
for the first calendar week. Positions three
and four represent the year of ma nufa
cture.
For example, a tire that is marked with
"3208", was manufactured in week 32 in
2008.
iTire data is vehicle-specific and may devi-
ate from the data in the example.
380All about wheels an d tires
Wheels and tires
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, occu-
pants, fuel, luggage and the drawbar nose-
weight, if applicable). The gross vehicle
weight rating is specified on the vehicle iden-
tification 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 corre-
sponds to 1 psi. Another unit for tire pressure is bar. 100 kilopascals (kPa) are the equiva-
lent of 1 bar.
Load index
In addition to the load-bearing index, the load
index may also be imprinted on the sidewall of
the tire. This specifies the load-bearing capa-
city more precisely.
Curb weight
The weight of a vehicle with standard equip-
ment including the maximum capacity of fuel,
oil and coolant. It also includes the air-condi-
tioning 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 is the maximum
permissible weight in kilograms or lbs 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)
A standard unit of measure for tire pressure.
Aspect ratio
Relationship between tire height and tire
width in percent.
Tire pressure
This is pressure inside the tire applying an
outward force to each square inch of the
tire's
su
rface. The tire pressure is specified in
pounds per square inch (psi), in kilopascal
(kPa) or in bar. The tire pressure should only
be corrected when the tires are cold.
Cold tire pressure
The tires are cold:
Rif the vehicle has been parked without
direct sunlight on the tires for at least three
hours and
Rif the vehicle has not been driven further
than 1 mile (1.6 km)
Tread
The part of the tire that comes into contact
with the road.
Bead
The tire bead ensures that the tire sits
securely on the wheel. There are several steel
wires in the bead to prevent the tire from
coming loose from the wheel rim.
Sidewall
The part of the tire between the tread and the
bead.
Weight of optional extras
The combined weight of those optional extras that weigh more than the replaced standard
parts and more than 5 lbs (2.3 kg). These
optional extras, such as high-performance
brakes, level control, a roof rack or a high-
382All about wheels and tires
Wheels and tires
XOn light downhill gradients:place
chocks or other suitable items in front of
the wheels of the front and rear axle.
Raising the vehicle
GWARNING
If you do not position the jack correctly at the
appropriate jacking point of the vehicle, the
jack could tip over with the vehicle raised.
There is a risk of injury.
Only position the jack at the appropriate jack-
ing point of the vehicle. The base of the jack
must be positioned vertically, directly under
the jacking point of the vehicle.
!The jack is designed exclusively for jack-
ing up the vehicle at the jacking points.
Otherwise, your vehicle could be damaged.
Observe the following when raising the
vehicle:
RTo raise the vehicle, only use the vehicle-
specific jack that has been tested and
approved by Mercedes-Benz. If used incor-
rectly, the jack could tip over with the vehi- cle raised.
RThe jack is designed only to raise and hold
the vehicle for a short time while a wheel
is being changed. It is not suited for per-
forming maintenance work under the vehi-
cle.
RAvoid changing the wheel on uphill and
downhill slopes.
RBefore raising the vehicle, secure it from
rolling away by applying the parking brake and inserting wheel chocks. Do not disen-
gage the parking brake while the vehicle is
raised.
RThe jack must be placed on a firm, flat and
non-slip surface. On a loose surface, a
large, flat, load-bearing underlay must be
used. On a slippery surface, a non-slip
underlay must be used, e.g. rubber mats.
RDo not use wooden blocks or similar
objects as a jack underlay. Otherwise, the
jack will not be able to achieve its load-
bearing capacity due to the restricted
height.
RMake sure that the distance between the
underside of the tires and the ground does
not exceed 1.2 in (3 cm).
RNever place your hands and feet under the
raised vehicle.
RDo not lie under the vehicle.
RDo not start the engine when the vehicle is
raised.
RDo not open or close a door or the trunk lid
when the vehicle is raised.
RMake sure that no persons are present in
the vehicle when the vehicle is raised.
Vehicles with AMG wheels and hub caps:
the hub cap covers the wheel bolts. Before
you can un
screw the wheel bolts, you must
remove the hub cap. Two different variants
can be installed.
Vehicles with AMG wheels and plastic
hub caps:
Changing a wheel385
Wheels and tires
Z