pressure, to be used only temporarily in an
emergency.
Tire width:tire width:shows the nominal
tire width in millimeters.
Height-width ratio: height-width ratio;is
the ratio between tire height and tire width.
The aspect ratio is calculated by dividing the
tire width by the tire height. The resulting
quotient is given as a percentage.
Tire code: tire code=shows 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).
The load-bearing index: load-bearing index
A (also load index), is a code that contains
the maximum 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 238).
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 pounds, see( Y page 246).
For further information on the load bearing
index, see "Load index" ( Ypage 246).
Speed rating: speed ratingBspecifies the
approved maximum speed of the tire.
iTire data is vehicle-specific and may devi-
ate from the data in the example.
Regardless of the speed rating, always
observe the speed limits. Drive carefully and
adapt your driving style to the traffic condi-tions.
iSince 2009, tires in Europe which corre-
spond to the noise limitations of Directive
ECE-R 117 show an >>S<< (Sound) mark.
This identification follows the type approval number and has no connection with the
speed rating.
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)
Wup to 168 mph (270 km/h)
Yup to 186 mph (300 km/h)
ZR...Yup to 186 mph (300 km/h)
ZR...(..Y)over 186 mph (300 km/h)
ZRover 149 mph (240 km/h)
R Optionally, tires with a maximum speed of
over 149 mph (240 km/h) may have "ZR" in
the size description, depending on the
manufacturer (e.g. 245/40 ZR18).
The service specification is made up of
load-bearing index Aand speed rating B.
R If the size description of your tire includes
"ZR" and there are no service specifica-
tions, 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 ZR18 97 Y.In this exam-
ple, "97 Y" is the service specification. The letter "Y" represents the speed rating and
Tire labeling245
Wheels and tires
Z
the maximum speed of the tire is limited to
186 mph (300 km/h ).
R The size description for all tires with maxi-
mum speeds of over 186 mph (300 km/ h)
must include "ZR", andthe service specifi-
cation must be given in parentheses. Exam- ple: 275/40 ZR 18 (99 Y). Speed rating
"(Y)" indicates that the maximum speed of
the tire is over 186 mph (300 km/h). Ask
the tire manufacturer about the maximum
speed.
All-weather tires and winter tires
IndexSpeed rating
Q M+S 4up to 100 mph (160 km/h)
T M+S
4up to 118 mph (190 km/h)
H M+S 4up to 130 mph (210 km/h)
V M+S4up to 149 mph (240 km/h)
iNot 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). These tires
have been developed specifically for driv-
ing on snow.
When the electronic speed limiter is set, your vehicle is prevented from exceeding 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. Therequired speed rating for your vehicle can be
found in the "Tires" section ( Ypage 256).
Further information about reading tire data
can be obtained from any qualified specialist workshop.
Load index
In addition to the load bearing index, load rat-ing :may be imprinted after the letters that
identify speed rating Bon the sidewall of the
tire ( Ypage 244).
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 reinforcedtire
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
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.
4 Or M+S ifor winter tires.
246Tire labeling
Wheels and tires
Do not overload the tires by exceeding the
specified load limit. The maximum permissi-
ble load can be found on the vehicle's Tire andLoading Information placard on the B-pillar on
the driver's side ( Ypage 238).
iThe actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
DOT, Tire Identification Number (TIN)
U.S. tire regulations prescribe that every
manufacturer of new tires or retreader has to imprint a TIN in or on the sidewall of each tire produced.
The TIN is a unique identification number. The
TIN enables tire manufacturers to inform pur-
chasers of recalls and other safety-relevant
matters. It makes it possible for the pur-
chaser to easily identify the affected 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 :indicates 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.
For further information about retreaded tires,
see ( Ypage 230). 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 manufacture.
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.
Tire characteristics
This information describes the type of tire
cord and the number of layers in sidewall :
and under tire tread ;.
iTire data is vehicle-specific and may devi-
ate from the data in the example.
Definition of terms for tires and load-
ing
Tire ply composition and material used
Describes the number of layers or the number
of rubber-coated belts in the tread and the
sidewall of the tire. These are made of steel,
nylon, polyester and other materials.
Tire labeling247
Wheels and tires
Z
Bar
Metric unit for tire pressure. 14.5038 poundsper square inch (psi) and 100 kilopascals
(kPa) are the equivalent of 1 bar.
DOT (Department of Transportation)
DOT-marked tires fulfill the requirements of
the U S Department of Transportation.
Normal occupant weight
The number of occupants for which the vehi-
cle is designed multiplied by 68 kilograms
(150 lbs).
Uniform Tire Quality Grading Standards
A uniform standard to grade the quality of
tires with regards to tread quality, tire traction
and temperature characteristics. The quality
grading assessment is made by the manufac- turer following specifications from the U.S.
government. The ratings are molded into the
sidewall of the tire.
Recommended tire pressures
The recommended tire pressure applies to
the tires mounted at the factory.
The Tire and Loading Information placard con- tains the recommended tire pressures for
cold tires on a fully loaded vehicle and for the
maximum permissible vehicle speed.
The tire pressure table contains the recom-
mended pressures for cold tires for various
operating conditions, i.e. differing load and
speed conditions.
Increased vehicle weight due to
optional equipment
The combined weight of all standard and
optional equipment available for the vehicle,
regardless of whether it is actually installed
on the vehicle or not.
Rim
This is the part of the wheel on which the tire
is mounted.
GAWR (Gross Axle Weight Rating)
The GAWR is the maximum gross 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 identifica-
tion. It specifies the speed range for which the
tire is approved.
GTW (Gross Trailer Weight)
The GTW is the weight of a trailer including the weight of the load, luggage, accessories etc.
on the trailer.
GVW (Gross Vehicle Weight)
The gross vehicle weight includes the weight
of the vehicle including fuel, tools, the spare
wheel, accessories installed, occupants, lug-
gage and the drawbar noseweight, if applica-
ble. 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, 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.
248Tire labeling
Wheels and tires
Maximum loaded vehicle weight
The maximum weight is the sum of: Rthe curb weight of the vehicle
R the weight of the accessories
R the load limit
R the 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 notinclude 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 axleby 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 surface. The tire pressure is specified in
pounds per square inch (psi), in kilopascals
(kPa) or in bar. The tire pressure should only
be corrected when the tires are cold.
Cold tire pressure
The tires are cold:
R if the vehicle has been parked without
direct sunlight on the tires for at least three
hours and
R if 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 2.3 kg (5 lbs). These
optional extras, such as high-performance
Tire labeling249
Wheels and tires
Z
brakes, level control, a roof rack or a high-
performance battery, are not included in the
curb weight and the weight of the accesso-ries.
TIN (Tire Identification Number)
This is a unique identifier which can be used
by a tire manufacturer to identify tires, for
example for a product recall, and thus identifythe purchasers. The TIN is made up of the
manufacturer's identity code, tire size, tire
type code and the manufacturing date.
Load bearing index
The load bearing index (also load index) is a
code that contains the maximum load bearing capacity of a tire.
Traction
Traction is the result of friction between the
tires and the road surface.
TWR (Tongue Weight Rating)
The TWR specifies the maximum permissible
weight that the ball coupling of the trailer tow hitch can support.
Treadwear indicators
Narrow bars (tread wear bars) that are dis-
tributed over the tire tread. If the tire tread islevel with the bars, the wear limit of áin
(1.6 mm) has been reached.
Occupant distribution
The distribution of occupants in a vehicle at
their designated seating positions.
Total load limit
Nominal load and luggage load plus 150 lb
(68 kilograms) multiplied by the number of
seats in the vehicle.
Changing a wheel
Flat tire
The "Breakdown assistance" section ( Y page 216) contains information and notes
on how to deal with a flat tire.
Rotating the wheels
GWARNING
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.
Rotating front and rear wheels of differing
dimensions can render the general operating
permit invalid.
Always pay attention to the instructions and
safety notices in the section on "Changing a
wheel and mounting a spare wheel"( Y page 251).
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
250Changing a wheel
Wheels and tires
every 3,000 to 6,000 miles
(5,000 to 10,000 km), or earlier if tire wear
requires. Do not change the direction of
wheel rotation.
Clean the contact surfaces of the wheel and
the brake disc thoroughly every time a wheel
is rotated. Check the tire pressure and reac-
tivate the tire pressure monitor ( Ypage 235)
if necessary.
Direction of rotation
Tires with a specified direction of rotation
have additional benefits, e.g. if there is a risk
of hydroplaning. You will only gain these ben-
efits if the correct direction of rotation isobserved.
An arrow on the sidewall of the tire indicates
its correct direction of rotation.
You may mount the spare wheel against the
direction of rotation. Adhere to the time
restriction on use as well as the speed limi-
tation specified on the spare wheel.
Storing wheels
Store tires 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
GWARNING
When you remove the spare wheel from the
spare wheel bracket, the vehicle’s weight dis- tribution changes. If the vehicle is already
raised, the jack could tip over. There is a risk
of injury.
Remove the spare wheel from the spare wheel
bracket before lifting the vehicle.
X Prepare the vehicle as described (Y page 216). X
Remove the vehicle tool kit and the jack(Y page 214).
X Secure the vehicle to prevent it from rolling
away.
X Remove the spare wheel from the spare
wheel bracket ( Ypage 215).
iVehicles without a spare wheel or emer-
gency spare wheel are not equipped with a tire-change tool kit at the factory. For more
information on which tools are required to
perform a wheel change on your vehicle
e.g. lug wrench or jack, consult an author-
ized Mercedes-Benz Center.
Securing the vehicle to prevent it from
rolling away
X On level ground: place chocks or other
suitable items under the front and rear of
the wheel that is diagonally opposite the
wheel you wish to change.
X On 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.
The following must be observed when raising
the vehicle:
R To raise the vehicle, only use the vehicle-
specific jack that has been tested and
approved by Mercedes-Benz. If used incor-
Changing a wheel251
Wheels and tires
Z
rectly, the jack could tip over with the vehi-cle raised.
R The 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.
R Avoid changing the wheel on uphill and
downhill slopes.
R Before raising the vehicle, secure it from
rolling away by applying the parking brake
and inserting wheel chocks. Never disen-
gage the parking brake while the vehicle is
raised.
R The jack must be placed on a firm, flat and
non-slip surface. On a loose surface, a
large, load-bearing underlay must be used.
On a slippery surface, a non-slip underlay
must be used, e.g. rubber mats.
R Do 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.
R Make sure that the distance between the
underside of the tires and the ground does
not exceed 1.2 in (3 cm).
R Never place your hands and feet under the
raised vehicle.
R Never lie under the raised vehicle.
R Never start the engine when the vehicle is
raised.
R Never open or close a door or the tailgate
when the vehicle is raised.
R Make sure that no persons are present in
the vehicle when the vehicle is raised.
XUsing lug wrench :, loosen the bolts on
the wheel you wish to change by about one full turn. Do not unscrew the wheel bolts
completely.
Pump lever ;
X
Assemble the pump lever for the jack. It can
be found with the vehicle tool kit ( Y page 214).
252Changing a wheel
Wheels and tires