Wheels and tyres
246Wear indicators
The original tyres on your vehicle have 1.6 mm high “tread wear indicators”
⇒ page 245, fig. 189 , running across the tread. Depending on the make,
there will be six to eight of them evenly spaced around the tyre. Markings on
the tyre sidewall (for instance the letters “TWI” or other symbols) indicate the
positions of the tread wear indicators. The minimum tread depth required by
law is 1.6 mm (measured in the tread grooves next to the tread wear indica-
tors). Worn tyres must be replaced. Different figures may apply in export
countries ⇒.
Tyre pressure
Under-inflation or over-inflation will reduce the life of the tyres considerably
and also impair the car's handling. The inflation pressures are listed on a
sticker on the inside of the fuel tank flap.
Correct inflation pressures are very important, especially at high speeds. The
pressure should therefore be checked at least once a month and before
starting any long journey.
Tyre pressure monitoring (RKA+)*
Monitoring of the tyre pressures is based on the tyre pressures you have
stored. The tyre pressure monitoring system cannot function as intended if
you store tyre pressure settings for a normal load, but then drive with the
vehicle fully laden. The tyre pressure must be adapted to the actual load and
stored accordingly in the tyre pressure monitoring system ⇒ page 244.
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 ⇒page 245, fig. 190. All the tyres will then
last for about the same time. Wheel balance
The wheels on new vehicles are balanced. However, various factors encoun-
tered in normal driving can cause them to become unbalanced, 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 align-
ment checked by an Authorised Service Centre.
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 is worn down to
the tread wear indicators. Failure to do so 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 insufficient 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 pres-
sures.•I f t y r e s s h o w e x ce s s i v e w e a r, y o u s h o u l d h a v e t h e r u n n i n g g e a r ch e cke d
by an Authorised Service Centre.•Keep chemicals such as oil, fuel and brake fluid away from tyres.•Damaged wheels and tyres must be replaced immediately!For the sake of the environment
Under-inflated tyres will increase fuel consumption.
ExeoST_EN.book Seite 246 Donnerstag, 3. September 2009 12:24 12
