Porsche 911 Manual page 245

Information
At low temperatures, juddering noises caused by the
tyres can occur during manoeuvering or accelerating
out of curves on both dry and wet road surfaces.
The driving performance and comfort of summer
tyres is reduced at low temperatures below 7 °C.
Porsche therefore recommends that you fit winter
tyres on the vehicle when temperatures are below
7 °C.
Extremely low temperatures below –15 °C can
cause permanent damage to summer tyres.
Winter tyres are no longer suitable if their tread
depth is less than 4 mm.
Using snow chains
Snow chains can be fitted to the rear axle only, with
the tyre/wheel combinations listed under "Technical
Data" and marked for snow chain use.
e Use only the snow chains approved by Porsche
to guarantee sufficient clearance between the
wheel well and the chain.
e Remove ice and snow deposits in the wheel well
before installing the chains.
e Observe the different national regulations re-
garding maximum speeds.
Checking tyre tread
Most tyres have integrated wear indicators in the
centre of the tread. These wear indicators are lo-
cated in the main tread channels and display the
minimum tread depth of 1.6 mm.
e Check tyre tread regularly, particularly before
and after long journeys.
Measuring tyre tread depth
e Insert a commercially available tread depth
gauge or calliper in the tyre tread and measure
the tyre tread depth.
Information
Uneven tyre wear indicates a defect on the vehicle:
e Visit a qualified specialist workshop. Porsche
recommends a Porsche partner as they have
trained workshop personnel and the necessary
parts and tools.
Storing wheels
Tyres must not be more than 6 years old. Chemical
additives, which make the rubber in the tyre elastic,
lose their effect over the course of time and the
rubber becomes brittle. The age of a tyre can be
seen from the DOT code on the tyre sidewall. If the
last four digits are 3016, for example, the tyre was
manufactured in the 30th week of 2016.
e Always store wheels in cool, dry and dark condi-
tions. Tyres without rims should be stored in a
standing position.
e Do not store summer tyres or park vehicles fitted
with summer tyres at ambient temperatures be-
low –15 °C.
e Avoid contact with petrol, oil and grease.
Balancing wheels
As a precaution, have wheels balanced in spring
(summer tyres) and before winter (M+S tyres).
e Visit a qualified specialist workshop. Porsche
recommends a Porsche partner as they have
trained workshop personnel and the necessary
parts and tools.
Tyres and Wheels
Changing a wheel
Working under the
WARNING
vehicle
The vehicle can slip off the jack.
e Make sure that no one is in the vehicle when
jacking up and changing a wheel.
e Raise the vehicle only at the prescribed jacking
points on the vehicle underbody.
e Never jack up the vehicle when it is parked on a
surface that slopes up, down or to the side.
e Only use the jack to raise the vehicle for chang-
ing wheels.
e Always place the vehicle on solid supports when
working under the vehicle.
Information
The tools needed for changing wheels (jack, wheel
bolt wrench, mounting aids, etc.) are not included in
the standard scope of supply for the vehicle.
e For information on the tool required: Contact
your Porsche partner.
Information
The tyre and wheel sizes are different on each axle.
When removing the wheels, mark the direction of
rotation and position on each wheel and carry out
the installation according to these markings.
e Only use wheels/tyres with approved dimensions
for the relevant axle.
> Please refer to the vehicle registration docu-
ments or the "Technical data" chapter in this
Manual.
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