Wheels
Tyre useful life Fig. 152
Tyre tread wear indicators. Fig. 153
Diagram for changing wheels The useful life of tyres is dependent on tyre
pressure, driving style and fitting.
Wear indicators
The original tyres on your vehicle have
1.6 mm high “tread wear indicators”
››› Fig. 152 , running across the tread. De- pendin
g on the m ake, there will be 6 to 8 of
them evenly spaced around the tyre. Mark-
ings on the tyre sidewall (for instance the let-
ters “TWI” or other symbols) indicate the po-
sitions of the tread wear indicators. The mini-
mum tread depth required by law is 1.6 mm
(measured in the tread grooves next to the
tread wear indicators). Worn tyres must be re-
placed. Different figures may apply in export
countries ››› .
Tyre pressure
Incorrect tyre pressure causes premature
wear and could cause tyre blow-out. For this
reason, the tyre pressure should be checked
at least once per month ››› page 175.
Driving style
Fast cornering, heavy acceleration and hard
braking all increase tyre wear.
Changing wheels around
If the front tyres are worn considerably more
than the rear ones it is advisable to change
them around as shown ››› Fig. 153 . The use-
f u
l life of all the tyres will then be about the
same time.
Wheel balance
The wheels on new vehicles are balanced.
However, various factors encountered in nor-
mal driving can cause them to become unbal-
anced, which results in steering vibration. Unbalanced wheels should be rebalanced, as
they otherwise cause excessive wear on
steering, suspension and tyres. A wheel must
also be rebalanced when a new tyre is fitted.
Incorrect wheel alignment
Incorrect wheel alignment causes excessive
tyre wear, impairing the safety of the vehicle.
If tyres show excessive wear, you should
have the wheel alignment checked by a Tech-
nical Service.
WARNING
There is a serious danger of accidents if a tyre
bursts during driving!
● The tyres must be replaced at the latest
when the tread wear indicators are worn
››› page 177. Failure to follow this instruction
could result in an accident. Worn tyres do not
grip well at high speeds on wet roads. There
is also a greater risk of “aquaplaning”.
● At continuously high speeds, a tyre with in-
sufficient pressure flexes more. This causes it
to overheat. This can cause tread separation
and tyre blow-out. Risk of accident. Always
observe the recommended tyre pressures.
● If tyres show excessive wear, you should
have the running gear checked by a Technical
Service.
● Keep chemicals such as oil, fuel and brake
fluid away from tyres.
● Damaged wheels and tyres must be re-
placed immediately! » 177
Technical specifications
Advice
Operation
Safety
