Get Wheels and tires -> Definition of terms for tires and loading Guide for Mercedes C Class 4 Door Second Generation (2007-2013)

Tire characteristics

Tire data is vehicle-specific and may

deviate fromthe data in the example.

This information describes the type of tire

cord and the number of layers in

sidewall : and under tire tread ;.

Definition of terms for tires and

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 United States Department of

Transportation.

Normal occupant weight

The number of occupants for which the

vehicle is designed multiplied by

68 kilograms (150 lbs).

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 loading

331

Wheels and tires

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 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

corresponds to 1 psi. Another unit for tire

pressure is bar. 100 kilopascals (kPa) are the

equivalent of 1bar.

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.

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Definition of terms for tires and loading

Wheels and tires

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.

Tire pressure of cold tires

The tires are cold:

if the vehicle has been parked without

direct sunlightonthe tires for at least three

hours and

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

parts 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

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.

Occupant distribution

The distribution of occupants in a vehicle at

their designated seating positions.

Total load limit

Nominal load and luggage load plus 68 kg

(150 lbs) multiplied by the number of seats in

the vehicle.

Definition of terms for tires and loading

333

Wheels and tires

Wheels and tires -> Definition of terms for tires and loading for Your Mercedes C Class 4 Door Second Generation (2007-2013)

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