2014 MERCEDES-BENZ SLS AMG GT ROADSTER wheel

Gross axle weight rating:
the maximum
permissible weight that can be carried by one
axle (front or rear axle).
To ensure that your vehicle does not exceed
the maximum permissible values (gross
vehicle weight and maximum gross axle
weight rating), have your loaded vehicle
(including driver, occupants, cargo, and full
trailer load if applicable) weighed on a
suitable vehicle weighbridge. All about wheels and tires
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 0043,
tire traction 0044and heat resistance 0087. All
tires sold in North America are provided with
the corresponding quality class mark on the
sidewall of the tire, even though these
regulations do not apply to Canada.
Quality grades can be found, where
applicable, on the tire sidewall between the
tread shoulder and maximum tire width. Example:
R
Treadwear grade: 200
R Traction grade: AA
R Temperature grade: A
All passenger car tires must conform to the
statutory safety requirements in addition to
these grades.
i The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
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 climate conditions.
Traction
G
WARNING
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.
! Avoid wheelspin. This can lead to damage
to the drive train.
The traction grades – from highest to lowest
– are AA, A, B and C. Those grades represent
the tire's ability to stop on wet pavement as
measured under controlled conditions on
specified government test surfaces of asphalt
and concrete. A tire marked C may have poor
traction performance. All about wheels and tires
261Wheels and tires Z

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
freezing point.
Mercedes-Benz recommends a minimum
tread depth of 00CFin(4 mm) on all four winter
tires. Observe the legally required minimum
tire tread depth (Y page 249). Winter tires can
reduce the braking distance on snow-covered
surfaces in comparison with summer tires.
The braking distance is still much further than
on surfaces that are not icy or covered with
snow. Take appropriate care when driving.
Further information on winter tires (M+S
tires) (Y page 250).
Temperature G
WARNING
The temperature grade for this tire is
established for a tire that is properly inflated
and not overloaded. Excessive speed,
underinflation, or excessive loading, either
separately or in combination, can cause
excessive heat build-up and possible tire
failure.
The temperature grades are A (the highest),
B, and C. They represent the tire's resistance
to the generation of heat 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 grade C corresponds 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 The following markings are on the tire in
addition to the tire name (sales designation)
and the manufacturer's name:
0043
Uniform Tire Quality Grading Standard
(Ypage 266)
0044 DOT, Tire Identification Number
(Ypage 265)
0087 Maximum tire load (Y page 265)
0085 Maximum tire pressure (Y page 254)
0083 Manufacturer
0084 Tire material (Y page 266)
006B Tire size designation, load-bearing
capacity and speed rating (Y page 262)
006C Load index (Y page 265)
006D Tire 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. 262
All about wheels and tiresWheels 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. 0043
Tire width
0044 Nominal aspect ratio in %
0087 Tire code
0085 Rim diameter
0083 Load bearing index
0084 Speed rating
i Tire data is vehicle-specific and may
deviate from the data in the example.
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
pressure, to be used only temporarily in an
emergency.
Tire width: tire width0043shows the nominal
tire width in millimeters. Aspect ratio:
aspect ratio0044is 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 code0087specifies 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
manufacturer (e.g. 245/40 ZR 18).
Rim diameter: rim diameter0085is 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 index0083
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 258).
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
(Y page 265).
For further information on the load bearing
index, see "Load index" (Y page 265).
Speed rating: speed rating0084specifies the
approved maximum speed of the tire.
Regardless of the speed rating, always
observe the speed limits. Drive carefully and
adapt your driving style to the traffic
conditions. All about wheels and tires
263Wheels and tires Z

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 118 mph (190 km/h)
H up to 130 mph (210 km/h)
V up to 149 mph (240 km/h)
W up to 168 mph (270 km/h)
Y up to 186 mph (300 km/h)
ZR...Y up to 186 mph (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 "ZR"
in the size description depending on the
manufacturer (e.g. 245/40 ZR 18).
The service specification is made up of
load-bearing index 0083and speed rating
0084.
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 index
and the maximum speed of the tire is
limited to 186 mph (300 km/h).
R The size description for all tires with
maximum speeds of over
186 mph (300 km/h) must include "ZR"
and the service specification must be given
in brackets. Example: 275/40 ZR 18 (99 Y). The speed index "(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
7 up to 100 mph (160 km/h)
T M+S
7 up to 118 mph (190 km/h)
H M+S
7 up to 130 mph (210 km/h)
V M+S
7 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 004Dsnowflake 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 snow traction, and were specially
developed for driving on snow.
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 for your vehicle as specified in
the "Tires" section (Y page 273), e.g. if you
buy new tires.
Further information about reading tire data
can be obtained from any qualified specialist
workshop.
7 Or M+S004D for winter tires.264
All about wheels and tiresWheels and tires

Load index
i
Tire data is vehicle-specific and may
deviate from the data in the example.
In addition to the load-bearing index, load
index 0043may be imprinted after the letters
that identify speed rating 0084(Ypage 262) on
the sidewall of the tire.
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
Maximum load rating Maximum tire load
0043is the maximum
permissible weight for which the tire is
approved.
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 258).
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 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 tire manufacturers 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 0044, tire size0087, tire type
code 0085and manufacturing date 0083.
i Tire data is vehicle-specific and may
deviate from the data in the example.
DOT (Department of Transportation): tire
symbol 0043marks that the tire complies with
the requirements of the U.S. Department of
Transportation.
Manufacturer identification code:
manufacturer identification code 0044provides
details on the tire manufacturer. New tires
have a code with two symbols.
Tire size: identifier0087describes the tire size. All about wheels and tires
265Wheels and tires Z

Tire type code:
tire type code0085can be used
by the manufacturer as a code to describe
specific characteristics of the tire.
Date of manufacture: date of manufacture
0083 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.
Tire characteristics i
Tire data is vehicle-specific and may
deviate from the data in the example.
This information describes the tire cord and
the number of layers in sidewall 0043and under
tire tread 0044.
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. There are
14.5038 pounds per square inch (psi) to
1 bar; there are 100 kilopascals (kPa) to 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 the vehicle is
designed to seat, 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
manufacturer following specifications from
the U.S. government. The ratings are molded
into the sidewall of the tire.
Recommended tire pressures
The recommended tire pressure for your
vehicle under normal driving conditions. You
will find the recommendation on the Tire and
Loading Information placard on the B-pillar on
the driver's side of your vehicle. The
recommended tire pressure provides the best
balance between handling characteristics,
ride comfort and wear. Supplemental
information pertaining to special driving
situations can be found on the tire inflation
pressure label on the inside of the fuel filler
flap.
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 permissible axle
weight. The actual load on an axle must never
exceed the gross axle weight rating. The
gross axle weight rating can be found on the 266
All about wheels and tiresWheels and tires

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 permitted gross
weight of the fully loaded vehicle (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 the curb
weight of the vehicle, the weight of the
accessories, the total load limit and the
weight of the optional equipment installed at
the factory.
Kilopascal (kPa)
Metric unit for tire pressure. 6.9 kPa is the
equivalent of 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. 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)
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. For this,
the vehicle must have been stationary for at
least three hours or not have traveled more
than 1.6 km (1 mile) in this time.
Tire pressure of cold tires
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 more than
1 mile (1.6 km) All about wheels and tires
267Wheels and tires Z

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
part 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
This is indicated by narrow bars (treadwear
bars) that are distributed over the tire tread.
If the tire tread is level with the bars, the wear
limit of 1
/ 16 in (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) times the vehicle's
designated seating capacity.
Changing a wheel
Flat tire
The "Breakdown assistance" section
(Y page 233) contains information and notes
on how to deal with a flat tire. Rotating 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 pay attention to the instructions and
safety notes when changing a wheel
(Y page 269).
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. 268
Changing a wheelWheels and tires