Wh eels and tir es, All about wheels and tires – Mercedes-Benz CLA-Class 2015 User Manual

Page 342

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 is the maximum

permissible weight in kilograms or lbs 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.
Cold tire pressure
The tires are cold:

if the vehicle has been parked without

direct sunlight on the 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 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 á in

(1.6 mm) has been reached.

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All about wheels and tires

eels

and

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