Porsche Cayman Owner's Manual page 221

Parking at the curb
Warning!
Hard impacts against curbs (or traffic
islands) are dangerous and may cause hid-
den tire damage which is not noticeable until
later. Such damage can result in accidents at
high speeds causing serious personal injury
or death.
Depending on the force of impact, the edge
of the rim can also be damaged.
f If you are in doubt, have the wheel checked by
an expert, particularly if you suspect damage
on the inside.
f If you must drive over a curb or other obstacle,
drive slowly and at an obtuse angle. Exercise
care when parking along curbs.
Wheel alignment, wheel balancing
As a precaution, have wheels with summer tires
balanced in the spring, and those with mud and
snow tires before winter.
Unbalanced wheels may affect car handling and
tire life.
Only the specified weights may be used for wheel
balancing.
Self-adhesive weights must not come into contact
with cleaning agents, since they could drop off.
Uneven tread wear indicates wheel imbalance. In
this event, the vehicle should be checked at an au-
thorized Porsche dealer.
Warning!
If, during a trip, uneven running or vibrations
occur that could be caused by damage to
tires or the car, the speed must be reduced
immediately, but without braking sharply.
If you continue your trip without having the
cause of the fault remedied, you might lose
control of your vehicle which could cause se-
rious personal injury or death.
f Stop the vehicle and check the tires.
f If no cause for the fault can be found, drive
carefully to the nearest authorized Porsche
dealer.
Wheels with Tire Pressure Monitoring
(TPM) sensors
Before changing wheels, make sure that the
wheels are compatible with your vehicle's TPM.
f Check this with your authorized Porsche
dealer.
Removing and storing tires
f After changing, adjust tire pressure and torque
wheel bolts diagonally to 94 ftlb (130 Nm).
Tires must always remain on the same side of
the vehicle.
When wheels are removed, the direction of
rotation and position of each wheel should be
marked.
Example
FR (front right), FL, RR and RL.
Wheels must always be fitted in accordance with
their marking.
The perception that tire durability and perform-
ance are immune to the effects of storage and
age is unfounded.
Chemical additives, which make the rubber elas-
tic, lose their effectiveness in the course of time
and the rubber becomes brittle and cracks.
Therefore, the tires should be inspected from
time to time.
Practical Tips, Emergency Service
219