
Therefore, only use tire types and sizes
approved for your vehicle model. Observe the
tire load rating and speed rating required for
your vehicle.
:Tire width
;Nominal aspect ratio in %
=Tire code
?Rim diameter
ALoad bearing index
BSpeed rating
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: compactemergency 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 578).
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 ma
ximum
tire load in kilograms and lbs, see
(
Ypage 585).
For further information on the load bearing
index, see "Load index" (
Ypage 585).
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.
All about wheels and tires583
Wheels and tires
Z

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 (
Ypage 593).
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 on the sidewall of the tire
(
Ypage 582).
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 load rating :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 578).
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 tire
manufacturer or retreader must imprint a TIN in or on the sidewall of every tire produced.
The TIN is a unique identification number. The
TIN makes it easier for tire manufacturers or
retreaders to notify customers of recalls or
other safety-related matters. It makes it pos-
sible for the purchaser to easily identify the
affected tires.
All about wheels and tires585
Wheels and tires
Z

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 been driven for less 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 kilograms (5 lbs).
These optional extras, such as high-perform-
ance brakes, level control, a roof rack or a
high-performance battery, are not included in
the curb weight and the weight of the acces-
sories.
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 identify
the 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.
Treadwear indicators
Narrow bars (tread wear bars) that are dis-
tributed over the tire tread. If the tire tread is
level 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
Rated cargo and luggage load plus
68 kilograms (150 lb) multiplied by the num-
ber of seats in the vehicle.
Changing a wheel
Flat tire
The "Breakdown assistance" section
(
Ypage 550) 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"
(
Ypage 551).
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.
588Changing a wheel
Wheels and tires

The folding wheel chock is an additional
securing measure to prevent the vehicle from
rolling away, for example when changing a
wheel.
XFold both plates upwards:.
XFold out lower plate;.
XGuide the lugs on the lower plate fully into
the openings in base plate =.
Securing the vehicle on level ground
XOn 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.
Securing the vehicle on slight downhill gradients
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 vehi-
cle:
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. Never 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.
590Changing a wheel
Wheels and tires