2013 MERCEDES-BENZ E-Class CABRIOLET tires

represent higher levels of performance on the
laboratory test wheel than the minimum
required by law.
Tire labeling
Overview :
Uniform Tire Quality Grading Standard
(Y page 342)
; DOT, Tire Identification Number
(Y page 341)
= Maximum tire load ( Y page 340)
? Maximum tire pressure (Y page 328)
A Manufacturer
B Tire material ( Y page 341)
C Tire size designation, load-bearing
capacity and speed index
(Y page 338)
D Load index ( Y page 340)
E Tire name
The markings described above are on the tire
in addition to the tire name (sales
designation) and the manufacturer's name.
i Tire data is vehicle-specific and may
deviate from the data in the example. Tire size designation, load-bearing
capacity and speed rating G
WARNING
Exceeding the stated tire load-bearing
capacity and the approved maximum speed
could

lead to tire damage or the tire bursting.
There is a risk of accident.
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
A Load bearing index
B Speed 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
description (as shown above): these are
passenger vehicle tires according to
European manufacturing 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.
manufacturing standards.
If "T" precedes the size description: these are
compact emergency spare wheels at high tire 338
All about wheels and tires
Wheels and tires

pressure, to be used only temporarily 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 a “ZR”
in the size description, depending on the
manufacturer (e.g. 245/40 ZR 18).
Rim diameter: rim diameter ? is the
diameter of the bead seat, not the diameter
of the rim flange. The rim diameter is
specified in inches (in).
Load-bearing index: load-bearing index A
is a numerical code that specifies the
maximum load-bearing capacity of a tire.
Do not overload the tires by exceeding the
specified load limit. The maximum
permissible load can be found on the
vehicle's Tire and Loading Information
placard on the B-pillar on the driver's side
(Y page 333).
Example:
The load bearing index 91 is equivalent to a
maximum load of 1356 lb (615 kg) that the
tire can carry. For further information on the
maximum tire load in kilograms and lbs, see
(Y page 340).
For further information on the load bearing
index, see "Load index" ( Y page 340).
Speed rating: speed rating B specifies the
approved maximum speed of the tire.
i Tire data is vehicle-specific and may
deviate 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
conditions.
Summer tires
Index Speed rating
Q up to 100 mph (160 km/h)
R up to 106 mph (170 km/h)
S up to 112 mph (180 km/h)
T up to 118mph (190 km/h)
H up to 130mph (210 km/h)
V up to 149 mph (240 km/h)
W up to 168 mph (270 km/h)
Y up to 186mph (300 km/h)
ZR...Y up to 186mph (300 km/h)
ZR...(..Y) over 186 mph (300 km/h)
ZR over 149 mph (240 km/h)
R
Optionally, tires with a maximum speed of
over

149 mph (240 km/h) may have a “ZR”
in the size description, depending on the
manufacturer (e.g. 245/40 ZR18).
The service specification is made up of
load-bearing index A and speed rating
B.
R If the size description of your tire 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).
R Every tire that has a maximum speed of
more than 186 mph (300 km/h) must have
a "ZR" in the size description and the
service specification must be given in All about wheels and tires
339
Wheels and tires Z

parentheses. Example:
275/40
ZR 18 (99 Y). The 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 Index Speed rating
Q M+S
3 up to 100 mph (160 km/h)
T M+S
3 up to 118mph (190 km/h)
H M+S
3 up to 130mph (210 km/h)
V M+S
3 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 i snowflake symbol on
the tire wall. 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 ( Y page 349).
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 index B on the sidewall
of the tire (Y page 338).
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
deviate from the data in the example.
Maximum load rating Maximum tire load
: is the maximum
permissible weight for which the tire is
approved.
3 Or M+S i for winter tires.340
All about wheels and tires
Wheels and tires

Do not overload the tires by exceeding the
specified load limit. The maximum
permissible load can be found on the
vehicle's Tire and Loading Information
placard on the B-pillar
on the driver's side
(Y page 333).
i The 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 enables the tire manufacturers or
retreaders

to inform purchasers of recalls and
other safety-relevant matters. It makes it
possible for the purchaser to easily identify
the affected tires.
The TIN is made up of manufacturer
identification 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:
manufacturer 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 ( Y page 322). 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.
i Tire data is vehicle-specific and may
deviate 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 ;.
i Tire data is vehicle-specific and may
deviate from the data in the example.
Definition

of terms for tires and loading Tire ply composition and material used
Describes

the number of plies or the number
of layers of rubber-coated fabric in the tire
tread and sidewall. These are made of steel,
nylon, polyester and other materials.
Bar
Metric unit for tire pressure.
14.5038 pounds per square inch (psi) and All about wheels and tires
341
Wheels and tires Z

100 kilopascals (kPa) are the equivalent of
1 bar.
DOT (Department of Transportation)
DOT marked tires fulfill the requirements of
the United States Department of
Transportation.
Normal occupant weight
The number of occupants for which the
vehicle is designed multiplied by
68 kilograms (150 lb).
Uniform Tire Quality Grading Standards
A uniform standard to grade the quality of
tires
with regards to tread quality, tire traction
and temperature characteristics. Ratings are
determined by tire manufacturers using U.S.
government testing procedures. The ratings
are molded into the sidewall of the tire.
Recommended tire pressure
The recommended tire pressure applies to
the tires mounted at the factory.
The Tire and Loading Information placard
contains 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
recommended pressures for cold tires for
various operating conditions, i.e. differing
load and speed conditions.
Increased vehicle weight due to optional
equipment
This is 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
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:
R the 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
corresponds to 1 psi. Another unit for tire
pressure is bar. There are 100 kilopascals
(kPa) to 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
capacity more precisely. 342
All about wheels and tires
Wheels and tires

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 tire load 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
surface. 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:
R if the vehicle has been parked without
direct sunlight on the tires for at least three
hours and
R if 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-
performance brakes, level control, a roof rack
or a high-performance battery, are not
included in the curb weight and the weight of
the accessories.
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
distributed over the tire tread. If the tire tread
is level with the bars, the wear limit of á in
(1.6 mm) has been reached. All about wheels and tires
343
Wheels and tires Z

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
number of seats in the vehicle.
Changing a wheel
Flat tire
You can find information on what to do in the
event of a flat tire in the "Breakdown
assistance" section (Y page 308).
Instructions for driving with MOExtended
tires in the event of a flat tire are also provided
there.
The "Breakdown assistance" section
(Y page 308) contains information and notes
on how to deal with a flat tire. Instructions for
driving with MOExtended tires in the event of
a flat tire are also provided there. Interchanging 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
accident.
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
located in the wheel.
Tire-mounting tools should not be used
near the valve. This could damage the
electronic components.
Only have tires changed at a qualified
specialist workshop. Always observe the instructions and safety
notes in the "Mounting a wheel" section
(Y page 345).
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
intervals in the tire manufacturer's warranty
book in your vehicle documents. If this is not
available, the tires should then be replaced
every 3,000 to 6,000 miles (5,000 to
10,000 km), or earlier if the tire wear requires
this. 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 interchanged. Check the tire pressure and,
if necessary, 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. You will only gain these
benefits if the correct direction of rotation is
maintained.
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. Cleaning the wheels
G
WARNING
The water jet from a circular jet nozzle (dirt
blasters)
can cause invisible exterior damage344
Changing a wheel
Wheels and tires

to the tires or chassis components.
Components damaged in this way may fail
unexpectedly. There is a risk of an accident.
Do not use power washers with circular jet
nozzles to clean the vehicle. Have damaged
tires or chassis components replaced
immediately.
Mounting a wheel
Preparing the vehicle X
Park the vehicle on firm, non-slippery and
level ground.
X Apply the parking brake.
X Bring the front wheels into the straight-
ahead position.
X Shift the transmission to position P.
X Switch off the engine.
X Vehicles without KEYLESS-GO: remove
the SmartKey from the ignition lock.
X Vehicles with KEYLESS-GO: open the
driver's door.
The on-board electronics have status 0,
which is the same as the SmartKey having
been removed.
X Vehicles with KEYLESS-GO: remove the
Start/Stop button from the ignition lock
(Y page 151).
X If included in the vehicle equipment, take
the tire-change tool kit out of the vehicle.
X Secure the vehicle to prevent it from rolling
away. Securing the vehicle to prevent it from
rolling away If your vehicle is equipped with a wheel chock,
it can be found in the tire-change tool kit
(Y page 308).
The folding wheel chock is an additional
securing
measure to prevent the vehicle from
rolling away, for example when changing a
wheel.
X Fold both plates upwards :.
X Fold out lower plate ;.
X Guide the lugs on the lower plate fully into
the openings in base plate =. Securing the vehicle on level ground (example:
Coupe)
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. Changing a wheel
345
Wheels and tires Z