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294Vehicle care
The legally permissible minimum
tread depth (1.6 mm) has been
reached when the tread has worn
down as far as one of the tread wear
indicators (TWI). Their position is
indicated by markings on the
sidewall.
Tyres age, even if they are not used.
We recommend tyre replacement
every 6 years.
Changing tyre and wheel
size
If tyres of a different size than those fitted at the factory are used, it may be necessary to reprogramme the
nominal tyre pressure and make
other vehicle modifications.
After converting to a different tyre
size, have the label with tyre
pressures replaced.
Tyre pressure monitoring system
3 291.9 Warning
The use of unsuitable tyres or
wheels may lead to accidents and will invalidate the vehicle
operating permit.
Wheel covers
Wheel covers and tyres that are
factory approved for the respective
vehicle and comply with all of the
relevant wheel and tyre combination
requirements must be used.
If the wheel covers and tyres used are
not factory approved, the tyres must
not have a rim protection ridge.
Wheel covers must not impair brake
cooling.9 Warning
Use of unsuitable tyres or wheel
covers could lead to sudden
pressure loss and thereby
accidents.
Tyre chains
Tyre chains are only permitted on the
drive wheels.
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302Vehicle care
Place wheel below the vehicle frame,
directly beneath the winch
mechanism.
Then tighten cable using the wheel
wrench and adapters by connecting
to the slot position illustrated above
and turning wrench anticlockwise
until the wheel is secured in the fully
raised position.
Notice
Do not place a wheel with aluminium rim under the vehicle frame.9 Warning
Ensure the front of the wheel (side
with tyre valve) is facing upwards
when the spare wheel is
reinstalled below the vehicle
frame.
Temporary spare wheel
Caution
The use of a spare wheel that is smaller than the other wheels or in combination with winter tyres
could affect driveability. Have the defective tyre replaced as soon as
possible.
Only mount one temporary spare
wheel. Do not drive faster than
50 mph. Take curves slowly. Do not
use for a long period of time.
Separately supplied bolts must be
used for the temporary spare wheel. These are allowed only for the
temporary spare wheel. Refer to an label on the temporary spare wheel.
Tyre chains 3 294.
Summer and winter tyres
If you use winter tyres, the spare
wheel may still be fitted with a
summer tyre.
If you use the spare wheel when it is
fitted with a summer tyre the vehicle's driveability may be affected,
especially on slippery road surfaces.
Directional tyres Fit directional tyres such that they rollin the direction of travel. The rolling
direction is indicated by a symbol
(e.g. an arrow) on the sidewall.
Page 311 of 351

Vehicle care309UnderbodySome areas of the vehicle underbody
have a PVC undercoating while other
critical areas have a durable
protective wax coating.
After the underbody is washed, check the underbody and have it waxed if
necessary.
Bitumen / rubber materials could
damage the PVC coating. Have
underbody work carried out by a
workshop.
Before and after winter, wash the
underbody and have the protective
wax coating checked.
Towing equipment
Do not clean the coupling ball bar with
a steam-jet or high-pressure jet
cleaner.Interior care
Interior and upholstery
Only clean the vehicle interior,
including the instrument panel fascia
and panelling, with a dry cloth or
interior cleaner.
Clean leather upholstery with clear
water and a soft cloth. In case of
heavy soiling, use leather care.
The instrument cluster and the
displays should only be cleaned using
a soft damp cloth. If necessary use a
weak soap solution.
Clean fabric upholstery with a
vacuum cleaner and brush. Remove
stains with an upholstery cleaner.
Clothing fabrics may not be
colourfast. This could cause visible
discolourations, especially on light- coloured upholstery. Removable
stains and discolourations should be
cleaned as soon as possible.
Clean seat belts with lukewarm water or interior cleaner.Caution
Close Velcro fasteners as open
Velcro fasteners on clothing could damage seat upholstery.
The same applies to clothing with
sharp-edged objects, like zips or
belts or studded jeans.
Plastic and rubber parts
Plastic and rubber parts can be
cleaned with the same cleaner as
used to clean the body. Use interior cleaner if necessary. Do not use any
other agent. Avoid solvents and petrol in particular. Do not use high-
pressure jet cleaners.