Porsche Cayenne Owner's Manual page 288

Note
Under no circumstances should tires older than
6 years be used on your Porsche.
The age of the tire can be obtained from the "DOT"
code number. If, for example, the last three num-
bers read 1208, then the tire was produced in the
12th week of 2008.
Snow tires
The installation of Porsche approved winter tires is
recommended.
Use Porsche approved winter tires for grip on
snow and ice. For optimum performance, stud-
ding can be considered.
Check with your local Motor Vehicle Bureau for
possible restrictions.
Danger!
Risk of loss of control and damage to the
vehicle as well as serious personal injury or
death.
The standard tires profile and rubber mixture
are optimized for wet and dry driving condi-
tions, and may not prove favorable for snow
conditions.
f Install winter tires before driving in such condi-
tions.
288
Minor Repairs
Before mounting winter tires, consult with your
Porsche dealer. He has the technical information
necessary to advise you on wheel and tire compa-
tibility.
f Snow tires should have the same load capacity
as original equipment tires and should be
mounted on all four wheels.
Winter tires with studs should be run at mode-
rate speeds when new in order to give the
studs time to settle.
Danger!
Risk of serious personal injury or death.
Driving the vehicle with low tire pressure
increases increases risk of a tire failure and
resulting loss of control. Furthermore, low
tire pressure increases rate of wear of the
affected tires and cause damage.
Tires with badly worn treads and studs are
very dangerous and could cause accidents
resulting in serious personal injuries or
death.
f Make sure they are replaced immediately.
f Do not exceed the winter tire speed rating.
Snow tires do not have the same degree of trac-
tion on dry, wet or snowfree roads as normal tires.
Furthermore, snow tires wear rapidly under these
conditions.
Maintenance Note
We recommend fitting winter tires on the vehicle at
temperatures below 45 °F (7 °C) since the driving
performance of summer tires is reduced at low
temperatures. Summer tires may be permanently
damaged at extremely low temperatures.
Winter tires do not fulfill their purpose if the tread
depth is less than 5/32 in. (4 mm).
Comply with all state and local laws gover-
ning snow tire and tread depth requirements.
Danger!
Risk of accident and serious personal injury
or death due to excessive speed.
f Always check the maximum speed rating on
the tire sidewall on any tire on the vehicle.
f Never exceed the maximum speed rating of
the tires.
Wheel change
f When wheels are removed, mark the direction
of rotation and position of each wheel.
Example: FR (front right), FL, RR and RL.
f Always fit the wheels in accordance with the
markings.