Porsche 928 GTS 1994 Owner's Manual page 91

Whenever you replace tires, make certain that
you install new valves. Initially, new tires do not
have their full traction. You should therefore
drive at moderate speeds during the first 60 -
120 miles ( 1 0 0 - 2 0 0 km).
If new tires are fitted only on one axle, a notice-
able change in handling occurs due to the differ-
ent tread depth of the other tires. This happens
especially if only rear tires are replaced. How-
ever, this condition disappears as the new tires
are broken in. Please adjust your driving style
accordingly.
Installation of new tires should only be done by
a qualified tire technician.
Wheel balancing
A wheel should always be balanced after a tire
repair. Even with regular use a wheel can get
out of balance, and should, therefore, be
balanced from time to time. Unbalanced wheels
may affect car handling and tire life.
When balancing wheels, use only balancing
weights supplied through the Porsche parts
service.
92
Wheels
If you intend to use other than original equip-
ment wheels, be sure that they conform to
Porsche specifications for your model.
Check with your Porsche dealer regarding the
correct wheel specifications for type and model
year.
Removing and storing tires
The driving direction should be clearly marked
on all tires before removing them for storage.
This is to make sure that they are mounted and
run in the same direction as before.
When fitting tires already mounted on rims, en-
sure that the colored wheel bolt is always
across from the valve. Always screw the locka-
ble wheel nut onto this bolt. When removing,
mark the direction of rotation on each wheel,
e.g. FR, FL, RR and RL. This precaution ensures
that the wheels will be remounted in the same
position, thus obviating the risk of imbalance.
The supposition that tires become long wearing
due to storage and age is unfounded. Chemical
additives, which make the rubber elastic, loose
their effectiveness in the course of time and the
rubber perishes. Therefore, the tires, espe-
cially the collapsible spare tire, should from
time to time undergo a visual check. For
this, pump up the collapsible spare tire.
Under no circumstances should tires be
older than 6 years.
The age of the tire can be seen from the "DOT"
code number. If, for example, the last three
numbers read 121, this means it was produced
in the 12th week of 1991.
Store tires in a cool and dry place.
Snow tires
For a better grip on snow and ice use radial
M+S tires or snow tires with studs. Check with
your local Motor Vehicle Bureau for possible re-
strictions.
WARNING
The standard tires profile and rubber mixture
are optimized for wet and dry driving condi-
tions, and may not prove favorable for snow
conditions. Therefore install M+S tires before
driving in such conditions. Failure to use the
proper tires and wheels could result in loss
of control and damage to the vehicle and
personal injury.