Tire tread
The part of the tire that comes into contact
with the road.
Tire 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 com-
ing loose from the wheel rim.
SidewallThe part of the tire between the tread and the
tire 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, a roof rack or a high-performance bat-
tery, are not included in the curb weight and
the weight of the accessories.
TIN (Tire Identification Number) A unique identification number which can be
used by a tire manufacturer to identify tires,
for example for a product recall, and thus iden-
tify the purchasers. The TIN is composed of
the manufacturer identification code, tire size,
tire model code and 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.
TWR (permissible trailer drawbar load)
The TWR is the maximum permissible weight
that may act on the ball coupling of the trailer
tow hitch.
Wear indicator Narrow bars (tread wear bars) that are distrib-
uted 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. Distribution of the vehicle occupants
The distribution of vehicle occupants over des-
ignated seat positions in a vehicle.
Maximum permissible payload weightNominal load and goods/luggage load plus
68 kg (150 lbs) multiplied by the number of
seats in the vehicle. Changing wheels
Rotating the wheels
! On vehicles equipped with a tire pressure
monitor, electronic components are located
in the wheel.
Tire-mounting tools should not be used near
the valve. This could damage the electronic
components.
Only have tires changed at a qualified spe-
cialist workshop.
Always observe the instructions and safety
notes under "Mounting a wheel"
(Y page
298).
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 tires according to the intervals
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 rotation.
Clean the contact surfaces of the wheel and
the brake disc thoroughly every time a wheel
is rotated. Avoid oily or greasy cleaning
agents.
Check the tire pressure and reactivate 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 benefits
if the correct direction of rotation is observed. Changing wheels
297
Wheels and tires Z
