2014 MERCEDES-BENZ CLA Owners Manual

Example 1Example 2Example 3
Step 3Permissible load and
trailer load/
noseweight
(maximum
permissible load
rating from the Tire
and Loading
Information placard
minus the gross
weight of all
occupants)
1500 lbs
(680 kg)
750 lbs
(340 kg) =
750 lbs (340 kg)
1500 lbs
(680 kg)
540 lbs
(245 kg) =
960 lbs (435 kg)
1500 lbs
(680 kg)
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 notexceeded. Details can
be found on the vehicle identificationplate on
the B-pillar on the driver's side of the vehicle
(Ypage 323).
Permissible gross vehicle weight:the
gross weight of the vehicle, all passengers,
load and trailer load/noseweight(if
applicable) must not exceed the permissible
gross vehicle weight.
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.
Trailer load/noseweight
The trailer load/noseweightaffects 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% and 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
permissible load can be found on the
vehicle's Tire and Loading Information
placard on the B-pillar on the driver's side
(Ypage 323).
Maximum tire loadis the maximum
permissible weight for which the tire is
approved.
iThe actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
Maximum load rating327
Wheels and tires
Z

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,
tire traction, and heat resistance".
These regulations do not apply to Canada.
Nevertheless, all tires sold in North America
are provided with the corresponding quality
grading markings 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
information can be found on the tire sidewall
between the tread shoulder and maximum
tire width.
iThe actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
For example:
TreadwearTractionTemperature
200AAA
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 climateconditions.
Traction
GWARNING
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.
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.Atire 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
surfaces.
You should pay special attention to road
conditions when temperatures are around
the freezing point.
Mercedes-Benz recommends a minimum
tread depth of\nin(4mm) for all four winter
tires (Ypage 314) to maintainnormal 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
considerably greater than when the road is
328Uniform Tire Quality Grading Standards
Wheels and tires

not covered with ice or snow. Take
appropriate care when driving.
!Avoid wheelspin. This can lead to damage
to the drive train.
Temperature
GWARNING
The temperature grade for this tire is
established for a tire thatis properly inflated
and not overloaded.Excessive speed,
underinflation, or excessive loading, either
separately or in combination, can cause
excessive heatbuild-up and possible tire
failure.
The temperature grades areA(the highest),
B, and C. These represent the tire's
resistance to the generationofheat 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 gradeCcorresponds 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 additionto the tire name (sales designation) and themanufacturer's name:
Uniform tire Quality Grading Standard
(Ypage 333)
DOT, Tire Identification Number
(Ypage 332)
"Maximum tire load (Ypage 327)
!Maximum tire pressure (Ypage 318)
Manufacturer
Tire material (Ypage 333)
Tire size designation, load-bearing
capacity and speed index (Ypage 330)
Load index (Ypage 332)
Tire name
iTire data is vehicle-specific and may
deviate from the data in the example.
Tire labeling329
Wheels and tires
Z

Tire size designation,load-bearing
capacity and speed rating
Tire width
Nominal aspectratio in %
"Tire code
!Rim diameter
Load bearing index
Speed rating
iTire 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 letterthat 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 widthshows the nominal
tire width in millimeters.
Nominal aspect ratio:aspect ratiois 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 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 149mph (240km/h) may have "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
is a numerical code which 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
(Ypage 323).
Example:
Aload-bearing index of 91 indicates a
maximum load of 1,356lb (615kg) that can be
carried by the tires. For further information on
the maximum tire load in kilograms and
pounds, see (Ypage 327).
For further information on the load-bearing
index, see Load index (Ypage 332).
Speed rating:speed rating specifies the
approved maximum speed of the tire.
GWARNING
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.
Regardless of the speed rating, always
observe the speed limits. Drive carefully and
330Tire labeling
Wheels and tires

adapt your driving style to the traffic
conditions.
Summer tires
IndexSpeed rating
Qup to 100mph (160 km/h)
Rup to 106mph (170 km/h)
Sup to 112mph (180 km/h)
Tup to 118mph (190 km/h)
Hup to 130mph (210 km/h)
Vup to 149mph (240 km/h)
Wup to 168mph (270 km/h)
Yup to 186mph (300 km/h)
ZR...Yup to 186mph (300 km/h)
ZR...(..Y)over 186mph (300 km/h)
ZRover 149mph (240 km/h)
ROptionally, tires with a maximum speed of
over149 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 indexand speed rating .
RIf the size description of yourtire 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).
RThe size description for all tires with
maximum speeds of over 186mph
(300km/h) must include "ZR",andthe
service specification 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
IndexSpeed rating
Q M+S5up to 100mph (160 km/h)
T M+S5up to 118mph (190 km/h)
H M+S5up to 130mph (210 km/h)
V M+S5up to 149mph (240 km/h)
iNot all tires with the M+S marking provide
the driving characteristics of winter tires.
Winter tires have, in additionto the M+S
identification, thesnow flake symbol
on the tire sidewall. 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 (Ypage 340).
Further information about reading tire data
can be obtained from any qualified specialist
workshop.
5Or M+Sfor winter tires.
Tire labeling331
Wheels and tires
Z

Load index
In addition to the load bearing index, load
indexmay be imprinted after the letters
that identify speed index (Ypage 330) on
the sidewall of the tire.
RIf no specificationis given: no text (as in the
example above), representsastandard
load (SL) tire
RXL or Extra Load: represents a reinforced
tire
RLightLoad: 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
deviate from the data in the example.
DOT, Tire Identification Number (TIN)
Canadiantire regulations prescribe that every
new tire manufacturer or retreader has to
imprintaTIN 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
possible for the purchaser to easily identify
the affected tires.
The TIN consists of the manufacturer
identification code, tire size", tire type
code!and manufacturing date.
DOT (Department of Transportation):tire
symbolindicates that the tire complies
with the requirements of the Canadian
Transport Ministry.
Manufacturer identification code:
manufacturer identification codeprovides
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
(Ypage 312).
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
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
deviate from the data in the example.
332Tire labeling
Wheels and tires

Tire characteristics
This informationdescribes the tire cord and
the number of layers in sidewalland under
tire tread.
iTire 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.
14.5038pounds 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 CanadianTransport Ministry.
Normal occupant weight
The number of occupants for which the
vehicle is designed multiplied by
68 kilograms (150 lb).
Uniform Tire Quality Grading
Standards
Auniform 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 Informationplacard
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 equipmentavailable for the
vehicle, regardless of whetheritis actually
installed on the vehicle or not.
Rim
This is the part of the wheel on which the tire
is mounted.
Definition of terms for tires and loading333
Wheels and tires
Z

GAWR (Gross Axle Weight Rating)
The GAWR is the maximumgross 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:
Rthe curb weight of the vehicle
Rthe weight of the accessories
Rthe load limit
Rthe 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. 100 kilopascal (kPa) is the
equivalent of1bar.
Load index
In addition to the load-bearing index, the load
index may also be imprinted on the sidewall
of the tire. This specifiesthe 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)
Astandard unitofmeasure for tire pressure.
334Definition of terms for tires and loading
Wheels and tires