tires MERCEDES-BENZ CLA-Class 2014 C117 Service Manual

Example 1 Example 2 Example 3
Step 3 Permissible load and
trailer load/nose-
weight (maximum
permissible load rat-
ing from the Tire and Loading Information
placard minus the
gross weight of all
occupants) 1500 lbs
(680 kg)
00F8
750 lbs (340 kg) = 750 lbs
(340 kg) 1500 lbs
(680 kg)
00F8
540 lbs (245 kg) =960 lbs
(435 kg) 1500 lbs
(680 kg) 00F8
150 lbs (68 kg) = 1350 lbs
(612 kg) Vehicle identification plate
Even if you have calculated the total cargo
carefully, you should still make sure that the
gross vehicle weight rating and the gross axle weight rating are not exceeded. Details can
be found on the vehicle identification plate on the B-pillar on the driver's side of the vehicle
(Y page 324).
Permissible gross vehicle weight: the
gross weight of the vehicle, all passengers,
load and trailer load/noseweight (if applica-
ble) must not exceed the permissible gross
vehicle weight.
Gross axle weight rating: the maximum per-
missible 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 vehi-
cle 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. Trailer load/noseweight
The trailer load/noseweight affects the gross
weight of the vehicle. If a trailer is attached,
the trailer load/noseweight is included in the
load along with occupants and luggage. The
trailer load/noseweight is usually between
10 %a nd 15% of the gross weight of the trailer
and its load. Maximum load rating
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 onthe driver's side (Y page 324). Maximum tire load
0043is the maximum per-
missible weight for which the tire is approved.
i The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration. Maximum load rating
327Wheels and tires Z

Uniform Tire Quality Grading Stand-
ards Overview of Tire Quality Grading
Standards
Uniform Tire Quality Grading Standards are
U.S. government specifications. Their pur-
pose is to provide drivers with uniform relia-
ble information on tire performance data. Tire
manufacturers have to grade tires using three
performance factors: tread wear 0043, tire trac-
tion 0044, and heat resistance 0087. These regu-
lations do not apply to Canada. Nevertheless,
all tires sold in North America are provided
with the corresponding quality grading mark- ings on the sidewall of the tire.
All passenger car tires must conform to the
statutory safety requirements in addition to
these grades.
Where applicable, the tire grading informa-
tion can be found on the tire sidewall between
the tread shoulder and maximum tire width.
i The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
For example: Treadwear Traction Temperature
200 AA A
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, how-
ever, and may depart significantly from the
norm, due to variations in driving habits, ser-
vice practices and differences in road char-
acteristics 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, cor- nering, hydroplaning, or peak traction char-
acteristics.
The traction grades, from highest to lowest,
are AA, A, B, and C. Those grades represent
the tire's ability to stop on a wet surface as
measured under controlled conditions on
specified government test surfaces of asphalt
and concrete. A tire marked C may have poor
traction performance.
The safe speed on a wet, snow covered or icy road is always lower than on dry road surfa-
ces.
You should pay special attention to road con-
ditions when temperatures are around the
freezing point.
Mercedes-Benz recommends a minimum
tread depth of 00CFin (4 mm) for all four winter
tires (Y page 316) to maintain normal driving
characteristics in winter. Winter tires can
reduce the braking distance on snow-covered surfaces in comparison with summer tires.
Stopping distance, however, is still consider-
ably greater than when the road is not cov-
ered with ice or snow. Take appropriate care
when driving.
! Avoid wheelspin. This can lead to damage
to the drive train. 328
Uniform Tire Quality Grading StandardsWheels and tires

Temperature
G
WARNING
The temperature grade for this tire is estab-
lished for a tire that is properly inflated and
not overloaded. Excessive speed, underinfla-
tion, 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. These represent the tire's resistance
to the generation of heat and its ability to dis- sipate 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 tempera-
ture 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 of tire labeling
The following markings are on the tire in addition to
the tire name (sales designation) and the manu-
facturer's name:
0043 Uniform tire Quality Grading Standard
(Ypage 333)
0044 DOT, Tire Identification Number
(Ypage 332)
0087 Maximum tire load (Y page 327)
0085 Maximum tire pressure (Y page 320)
0083 Manufacturer
0084 Tire material (Y page 333)
006B Tire size designation, load-bearing capa-
city and speed index (Y page 330)
006C Load index (Y page 332)
006D Tire name
i Tire data is vehicle-specific and may devi-
ate from the data in the example. Tire labeling
329Wheels and tires Z

Tire size designation, load-bearing
capacity and speed rating 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 devi-
ate 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 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: 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.
Nominal aspect ratio: aspect ratio0044is the
size ratio between the tire height and the 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 149mph (24 0km/h) may have "ZR" in
the size description, depending on the man-
ufacturer (e.g. 245/40 ZR 18).
Rim diameter: rim diameter0085is 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 index0083is
a numerical code which 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 (Y page 324).
Example:
A load-bearing index of 91 indicates a maxi-
mum load of 1,356lb (615kg) that can be car-
ried by the tires. For further information on
the maximum tire load in kilograms and
pounds, see (Y page 327).
For further information on the load-bearing
index, see Load index (Y page 332).
Speed rating: speed rating0084specifies the
approved maximum speed of the tire. G
WARNING
Exceeding the stated tire load-bearing capa-
city 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.
Regardless of the speed rating, always
observe the speed limits. Drive carefully and 330
Tire labelingWheels and tires

adapt your driving style to the traffic condi-
tions. Summer tires
Index Speed rating
Q up to 100mph (160 km/h)
R up to 106mph (170 km/h)
S up to 112mph (180 km/h)
T up to 118mph (190 km/h)
H up to 130mph (210 km/h)
V up to 149mph (240 km/h)
W up to 168mph (270 km/h)
Y up to 186mph (300 km/h)
ZR...Y up to 186mph (300 km/h)
ZR...(..Y) over 186mph
(300 km/h) ZR over 149mph
(240 km/h) R
Option ally, tires with a maximum speed of
over 149 mph (240km/h) may have "ZR" in the size description, depending on the
manufacturer (e.g. 245/40 ZR 18).
The service specifications consist of load
bearing index 0083and speed rating 0084.
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 ZR 18 97 Y. In this exam-
ple, "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 The size description for all tires with maxi-
mum speeds of over 186mph (300km/h)
must include "ZR", andthe service specifi-
cation must be given in brackets. Example: 275/40 ZR 18 (99 Y). The speed rating "(Y)"
indicates that the maximum speed of the
tire is over 186mph (300km/h). Ask the
tire manufacturer about the maximum
speed. All-weather tires and winter tires
Index Speed rating
Q M+S
3 up to 100mph (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 149mph (240 km/h)
i
Not all tires with the M+S marking provide
the driving characteristics of winter tires.
Winter tires have, in addition to the M+S
identification, the 004Dsnow flake symbol
on the tire sidewall. Tires with this marking
fulfill the requirements of the Rubber Man- ufacturers Association (RMA) and the Rub-
ber 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 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 (Y page 340).
Further information about reading tire data
can be obtained from any qualified specialist
workshop.
3 Or M+S 004Dfor winter tires. Tire labeling
331Wheels and tires Z

Load index
In addition to the load bearing index, load
index 0043may be imprinted after the letters
that identify speed index 0084(Ypage 330) 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
i Tire data is vehicle-specific and may devi-
ate from the data in the example. DOT, Tire Identification Number (TIN)
Canadian tire regulations prescribe that every
new tire manufacturer 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 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.
The TIN consists of the manufacturer identi-
fication code 0044, tire size0087, tire type
code 0085and manufacturing date 0083.
DOT (Department of Transportation): tire
symbol 0043indicates that the tire complies
with the requirements of the Canadian Trans-
port Ministry.
Manufacturer identification code: manu-
facturer identification code 0044provides
details on the tire manufacturer. New tires
have a code with two symbols. Retreaded
tires have a code with four symbols.
Further information about retreaded tires
(Y page 314).
Tire size: identifier0087describes the tire size.
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.
i Tire data is vehicle-specific and may devi-
ate from the data in the example. 332
Tire labelingWheels and tires

Tire characteristics
This information describes the tire cord and
the number of layers in sidewall 0043and under
tire tread 0044.
i Tire 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 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 100 kilopascals
(kPa) are the equivalent of 1 bar. DOT (Department of Transportation)
DOT marked tires fulfill the requirements of
the Canadian Transport Ministry. Normal occupant weight
The number of occupants for which the vehi-
cle is designed multiplied by 68 kilograms
(150 lb). Uniform Tire Quality Grading Stand-
ards
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 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
This is the combined weight of all standard
and optional equipment available for the vehi-
cle, regardless of whether it is actually instal-
led 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. Definition of
terms for tires and loading
333Wheels and tires Z

Speed rating
The speed rating is part of the tire identifica-
tion. 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, 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. 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 corre-
sponds to 1 psi. Another unit for tire pressure
is bar. 100 kilopascal (kPa) is the equivalent
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 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. 334
Definition of terms for tires and loadingWheels and tires

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. 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 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
part and more than 2.3 kg (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 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 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 00CDin
(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
68 kilograms (150 lb) multiplied by the num-
ber 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 "Flat tire" section
(Y page 296). Information on driving with
MOExtended tires in the event of a flat tire can Changing a
wheel
335Wheels an d tires Z

be found under "MOExtended tires (tires with
run-flat characteristics" (Y page 297).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 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.
Always pay attention to the instructions and
safety notes when changing a wheel
(Y page 335).
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
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 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 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 damage to the tires or chassis components. Compo-
nents damaged in this way may fail unexpect-edly. 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 imme-
diately. Mounting a wheel
Preparing the vehicle X
Stop the vehicle on solid, non-slippery and
level ground.
X Apply the electric parking brake manually
(Y page 158).
X Bring the front wheels into the straight-
ahead position.
X Move the DIRECT SELECT lever to position
P.
X Switch off the engine. 336
Changing a wheelWheels and tires