Wheels and Tyres209
Using the system
Safety
Driving Tips
General Maintenance
Breakdown assistance
Technical Data
The tyre inflation pressure for tyres of the tyre size 205/50 R17, which are intended to
be used with snow chains, is identical to the tyre inflation pressure for tyres of the tyre
size 225/45 R17, see
page 208, fig. 169 .
The tyre pressure should be at the highest pressure specified for your vehicle at all
times.
The tyre inflation pressure of the emergency spare wheel R 18 is 420 kPa (4.2 bar).
Always check the inflation pressure of tyres when cold. Do not reduce the higher pres-
sure of warm tyres. Adapt the inflation pressure of the tyres accordingly if your vehicle
is carrying a significantly higher payload.
Driving style
Fast cornering, sharp acceleration and brak ing (squealing tyres) increase wear-and-
tear on your tyres.
Balancing wheels
The wheels of a new vehicle are balanced. There are a wide range of influences when
driving which may result in an imbalance and which makes themselves felt through
vibration in the steering.
You should have the wheels rebalanced si nce any imbalance increases wear-and-tear
on the steering, the suspension and tyres. A wheel must also be rebalanced when a
new tyre is fitted and each time a tyre is repaired.
Wheel alignment errors
Incorrect wheel alignment at the front and re ar will not only increase wear-and-tear on
the tyres but will also has an adverse effect on vehicle safety. Contact your specialist
garage if you notice any unusual tyre wear.
WARNING
If the inflation pressure is too low, the tyre must perform a greater flexing
work. At higher speeds the tyre will warm up as a result of this. This can result
in tread separation and even a tyre blowout.
Immediately replace the damaged rims or tyres.
Tyres which are 6 years old or more should only be fitted in exceptional
cases and when adopting an approp riately cautious style of driving.
For the sake of the environment
Tyres which are insufficiently inflated increase your fuel consumption.Wear indicatorsThe base of the tread of the original tyres has wear indicators 1.6 mm high, installed at
right angles to the direction of travel. These wear indicators are located at 6 - 8 points
depending on the make and are evenly spaced around the circumference of the tyre
fig. 170 . Markings on the walls of the tyres through the letters “TWI”, triangular
symbols or other symbols identify th e position of the wear indicators.
A remaining tread of just 1.6 mm, measured in the grooves of the tread next to the wear
indicators, means that your tyres have reached their legally permissible minimum
tread depth.
WARNING
You must have your tyres replaced with new ones at the latest when the
wear indicators have been worn down . The legally permissible minimum tread
depth should be observed.
Worn tyres do not provide the necessary adhesion to the road surface at
high speeds on wet roads. One could experience “aquaplaning” (uncontrolled
movements of the vehicle - “swimming” on a wet road surface).
Fig. 170 Tyre tread with wear indicators
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