Tires/Wheels - Porsche 928 GTS 1994 Owner's Manual

Tires/Wheels

The original equipment tires and wheel rims on
your Porsche comply with all applicable Federal
Motor Vehicle Safety Standards.
For your driving safety remember the following:
• Wheel rims and wheel bolts are matched to fit
your Porsche.
• If you intend to use other than original equip-
ment wheels, be sure that they conform to
Porsche specifications for your model.
• The use of wheel rims and wheel bolts that do
not meet specifications of the original factory
installed equipment will affect the safe opera-
tion of your vehicle.
• Before you plan on exchanging wheels, or
snow tires already mounted on wheel rims,
consult your Porsche dealer. He has the tech-
nical information necessary to advise you
which wheel rims and wheel bolts are compat-
ible with the original factory installations.
Tire pressures
WARNING
Incorrect tire pressures cause increased tire
wear and adversely affect road holding of
the vehicle, leading to loss of control.
90
For safety reasons do not use tire inflating
bottles.
Always use an accurate tire pressure gauge
when checking inflation pressures. Do not
exceed the maximum tire inflation pressure
listed on the tire sidewalk (Also refer to
"Technical data"). Cold tire inflation pressure
means: when a car has not been driven for
at least 3 hours or less than 1 mile. Never
let any air out of warm tires to meet cold
tire pressure specifications.
Tire traction
WARNING
When driving on wet or slushy roads, a
wedge of water may build up between the
tires and the road. This phenomenon is
known as aquaplaning and may cause partial
or complete loss of traction, vehicle control
or stopping ability. Reduce speed on wet sur-
face.
Tire life
Tire life depends on various factors, i.e., roads,
traffic and weather conditions, driving habits,
type of tires and tire care.
Inspect your tires at least every 2000 miles or
3000 km for wear and damage. If you notice
uneven or substantial wear, wheels might need
alignment or tires should be balanced or re-
placed.
Tires must always remain on same side of
vehicle.
After changing, adjust tire pressure and torque
wheel nuts diagonally to 94 ftlb (130 Nm). See
"Changing wheels".
Tire wear
The original equipment tires on your Porsche
have built-in wear indicators. They are molded
into the bottom of the tread grooves and will
appear as approximately 1/2 in (12 mm) bands
when the tire tread depth is down to 1/16 of an
in (1.6 mm).
When the indicators appear in two or more adja-
cent grooves, it is time to replace the tires. We
recommend, however, that you do not let the
tires wear down to this extent. Worn tires can-
not grip the road surface properly and are even
less effective on wet roads.
In the United States, state laws may govern the
minimum tread depth permissible. Follow all
such laws.