2012 MERCEDES-BENZ E-Class CABRIOLET wheel

Example: step 1 to 3
The following table shows examples on how to calculate total and cargo load capacities with
varying seating configurations and number and size of occupants. The following examples use
a load limit of 1500 lbs. This is for illustration purposes only. Make sure you are using the
actual load limit for your vehicle stated on the vehicle’s Tire and Loading Information placard
( Y page 320).
Example 1Example 2Example 3Step 1Combined maximum
weight of occupants
and cargo (data from
the Tire and Loading
Information placard)1500 lbs
(680 kg)1500 lbs
(680 kg)1500 lbs
(680 kg)Example 1Example 2Example 3Step 2Number of people in
the vehicle (driver
and occupants)531Distribution of the
occupantsFront: 2
Rear: 3Front: 1
Rear: 2Front: 1Weight of the
occupantsOccupant 1:
150 lbs (68 kg)
Occupant 2:
180 lbs (82 kg)
Occupant 3:
160 lbs (73 kg)
Occupant 4:
140 lbs (63 kg)
Occupant 5:
120 lbs (54 kg)Occupant 1:
200 lbs (91 kg)
Occupant 2:
190 lbs (86 kg)
Occupant 3:
150 lbs (68 kg)Occupant 1:
150 lbs (68 kg)Gross weight of all
occupants750 lbs (340 kg)540 lbs (245 kg)150 lbs (68 kg)322Loading the vehicleWheels and tires

Example 1Example 2Example 3Step 3Permissible cargo
and trailer load/
noseweight
(maximum gross
vehicle weight 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)
The higher the weight of all the occupants, the smaller the maximum load for luggage.
Further information can be found under "Towing a trailer" ( Y page 323).
Vehicle identification plate
Even if you have calculated the total load
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 (Y page 319).
Gross vehicle weight: the gross weight of
the vehicle, all passengers, cargo and trailer
load/noseweight (if applicable) must not
exceed the permissible gross vehicle weight.
Gross axle weight rating: the maximum
permissible load 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/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
approximately 10% of the gross weight of the
trailer and its load.
Your Mercedes-Benz has been designed
primarily to carry passengers and their
luggage. Mercedes-Benz does not
recommend towing a trailer with your vehicle.
Maximum load rating
GWARNING
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard on the
driver's door B-pillar. Overloading the tires
can overheat them, possibly causing a
blowout. Overloading the tires can also result
in handling or steering problems, or brake
failure.
Maximum load rating323Wheels and tiresZ

iThe actual values for tires are specific to
each vehicle and may deviate from the
values in the illustration.
Maximum tire load : is the maximum
permitted weight for which the tire is
approved.
Further information on tire loads
( Y page 325).
Uniform Tire Quality Grading
Standards
Overview of Tire Quality Grading
Standards
The Uniform Tire Quality Grading is a U.S.
Government requirement. Their purpose is to
provide drivers with consistent and reliable
information regarding tire performance. Tire
manufacturers are required to grade tires
using three performance factors: tread
wear :, tire traction ;, and temperature
resistance =. Although not a Government of
Canada requirement, all tires made for sale in
North America have these grades branded on
the sidewall.
i The actual values for tires are vehicle-
specific and may deviate from the values in
the illustration.
Where applicable, the tire grading
information can be found on the tire sidewall
between the tread shoulder and maximum
tire width.
For example:Tread wearTractionTemperature200AAA
All passenger car tires must conform to the
statutory safety requirements in addition to
these grades.
Tread wear
The tread wear 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
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
324Uniform Tire Quality Grading StandardsWheels and tires

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.GWARNING
If ice has formed on the road, tire traction will
be substantially reduced. Under such weather
conditions, drive, steer and brake with
extreme caution.
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 tire
tread depth of 1
/ 6 in (4 mm) for all four winter
tires ( Y page 310) to maintain normal driving
characteristics in winter. Winter tires can
reduce the braking distance on snow covered
surfaces in comparison to summer tires.
Stopping distance, however, is still
considerably greater than when the road is
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 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. These 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
Tire labeling overview
The following markings are on the tire in
addition to the tire name (sales designation)
and the manufacturer's name:
:Uniform tire Quality Grading Standard
( Y page 329);DOT, Tire Identification Number
( Y page 328)=Maximum tire load ( Y page 323)?Maximum tire pressure ( Y page 314)AManufacturerBTire material ( Y page 329)CTire size designation, load-bearing
capacity and speed rating ( Y page 326)Tire labeling325Wheels and tiresZ

DLoad index (Y page 328)ETire 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
:Tire width;Nominal aspect ratio in %=Tire code?Rim diameterALoad bearing indexBSpeed 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 width : shows the nominal
tire width in millimeters.
Nominal aspect ratio: aspect ratio ; is 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 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 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 which specifies the
maximum load-bearing capacity of a tire.GWARNING
The tire load rating must always be at least
half of the GAWR of your vehicle. Otherwise,
sudden tire failure may be the result which
could cause an accident and/or serious injury
to you or others.
Always replace rims and tires with rims and
tires having the same specifications
(designation, manufacturer and type) as
shown on the original part.
GWARNING
Do not overload the tires by exceeding the
specified load limit as indicated on the Tire
and Loading Information placard on the
driver's door B-pillar. Overloading the tires
can overheat them, possibly causing a
blowout. Overloading the tires can also result
in handling or steering problems, or brake
failure.
326Tire labelingWheels and tires

Example:
The load bearing index 91 is equivalent to a
maximum load of 1356 lbs (615 kg) that the
tire can carry. For further information on the
maximum tire load in kilograms and pounds,
see ( Y page 323).
For further information on the load bearing
index, see Load index ( Y page 328).
Speed rating: speed rating B specifies the
approved maximum speed of the tire.GWARNING
Even when permitted by law, never operate a
vehicle at speeds greater than the maximum
speed rating of the tires.
Exceeding the maximum speed for which tires
are rated can lead to sudden tire failure,
causing loss of vehicle control and possibly
resulting in an accident and/or serious
personal injury and possible death, for you
and for others.
Regardless of the speed rating always
observe the speed limits. Drive carefully and
adapt your driving style to the traffic
conditions.
Summer tiresIndexSpeed ratingQUp to 100 mph (160 km/h)RUp to 106 mph (170 km/h)SUp to 112 mph (180 km/h)TUp to 118 mph (190 km/h)HUp to 130 mph (210 km/h)VUp to 149 mph (240 km/h)WUp to 168 mph (270 km/h)YUp to 186 mph (300 km/h)ZR...YUp to 186 mph (300 km/h)Summer tiresIndexSpeed ratingZR...(..Y)Above 186 mph (300 km/h)ZRAbove 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 specifications consist 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 (300 km/h).
R Every tire that has a maximum speed above
186 mph (300 km/h) must have "ZR" in the
size description and the service
specification must be given in brackets.
Example: 275/40 ZR 18 (99 Y). The speed
rating "(Y)" shows that the maximum speed
of the tire is above 186 mph (300 km/h).
Ask the tire manufacturer to find out the
maximum speed.
All-weather tires and winter tiresIndexSpeed ratingQ M+S 25Up to 100 mph (160 km/h)T M+S25Up to 118 mph (190 km/h)H M+S 25Up to 130 mph (210 km/h)V M+S25Up to 149 mph (240 km/h)25
Or M+S i for winter tires.Tire labeling327Wheels and tiresZ

iNot all tires that have the M+S
identification offer the driving
characteristics of winter tires. Winter tires
have, in addition to the M+S identification,
the i snow flake symbol on the tire
sidewall. Tires with this identification fulfill
the requirements of the Rubber
Manufacturers Association (RMA) and the
Rubber Association of Canada (RAC)
regarding the tire traction on snow and
have been especially developed for driving
on snow.
An electronic speed limiter prevents your
vehicle from exceeding a speed of
130 mph (210 km/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 as specified in the "Tires"
section ( Y page 333), e.g. if you buy new
tires.
Further information about reading tire data
can be obtained from any qualified specialist
workshop, e.g. an authorized Mercedes-Benz
Center.
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 : may be imprinted after the letters
that identify speed index B (Y page 326) 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
DOT, Tire Identification Number (TIN)
U.S. tire regulations prescribe that every
manufacturer of new tires 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 enables the 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 ;, tire size =, tire type
code ? and manufacturing date A.
i Tire data is vehicle-specific and may
deviate from the data in the example.
DOT (Department of Transportation): tire
symbol : indicates that the tire complies
with the requirements of the U.S. Department
of Transportation.
328Tire labelingWheels and tires

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.
Further information about retreaded tires
( Y page 308).
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.
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 : and under
the tread ;.
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 United States 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. 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
Definition of terms for tires and loading329Wheels and tiresZ