Wheels and Tyres241
Using the systemSafetyDriving TipsGeneral MaintenanceBreakdown assistanceTechnical Data
•The wheel bolts must be clean and must turn easily. However, they must
never be treated with grease or oil.
•If the wheel bolts are tightened to a too low tightening torque, the rim
can lossen when the car is moving - risk of accident! A tightening torque
which is too high can damage the bolts and threads and this can result in
permanent deformation of the contact surfaces on the rims.
Caution
The prescribed tightening torque of the wheel bolts for steel and light alloy wheels
is 120 Nm.
Winter tyres
The handling of your vehicle will be significantly improved when driving on wintry
roads if you fit winter tyres. Summer tyres do not offer the same grip on ice, snow
and at temperatures below 7 °C because of their construction (width, rubber blend,
tread pattern). This partic ularly applies to vehicles which are equipped with low-
profile tyres or high-speed tyres (code index H or V on wall of tyre).
Winter tyres must be mounted on all four wheels to obtain the best handling char-
acteristics.
You must only fit those types of winter tyre which are approved for your vehicle. The
permissible sizes of winter tyres are stated in your vehicle documents. Approvals
may differ because of national legislation.
Please remember that the tyres should be in flated to 20 kPa (0.2 bar) more than is
the case for summer tyres ⇒page 237.
Winter tyres no longer offer the same winter performance once the tyre tread has
worn down to a depth of about 4 mm.
Ageing also causes winter tyres to lose most of their winter performance properties
- even in cases where the remaining tread depth is still clearly more than 4 mm.
Speed restrictions apply to winter tyres as well as to summer tyres ⇒page 239,
⇒ . You can fit winter tyres of a lower speed ca
tegory to your vehicle provided that you
also do not drive faster than the permissible maximum speed for such tyres, even
if the possible maximum speed of your vehicle is higher. The corresponding tyre
category can damage the tyres when exceeding the permissible maximum speed.
Please pay attention to the notes if you decide to fit winter tyres ⇒page 237.
You can also fit so-called “all-year tyres” instead of winter tyres.
Please contact your specialist garage if there are any points which are not clear who
will be able to provide you with information regarding the maximum speed for your
tyres.
WARNING
You must on no account drive your car at more than the permissible
maximum speed for your winter tyres - risk of an accident resulting from
tyre damage and loss of control over your car.
For the sake of the environment
Fit your summer tyres on again in good ti me since summer tyres offer you better
grip and handling on roads which are free of snow and ice as well as ar tempera-
tures below 7 °C - the braking distance is shorter, there is less tyre noise, tyre wear
is reduced and fuel consumption is reduced.
Note
Please observe the various differing legal requirements regarding tyres.
Unidirectional tyres*
The direction of rotation of the tyres is marked by arrows on the wall of the tyre.
This indicates the direction of rotation of the tyre, and it is essential that the tyres
are fitted on to run in this direction. Only then are the tyres able to provide the
optimal properties in terms of grip, lo w noise, wear-and-tear and aquaplaning.
Should it be necessary to fit on a spare wheel in exceptional cases with a tyre not
dedicated to the running dire ction or in opposite running direction, please adopt a
WARNING (continued)
20A5Facelift.book Page 241 Saturday, September 6, 2008 2:13 PM
