Porsche 928 S4 – Owner’s Manual |
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Model Year 1987 From
the “Porsche 928 S4 Owner’s Manual”, available from 928 Specialists. |
The
original equipment tires on your Porsche comply with all applicable Federal
Motor Vehicle Safety Standards. For
your driving safety remember the following:
Tire pressures
WARNING Incorrect
tire pressures cause increased tire wear and adversely affect road holding of
the vehicle, leading to loss of control. Always use an accurate tire pressure gauge when checking
inflation pressures. Do not
exceed the maximum tire inflation pressure listed on the tire sidewall. (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 surface.
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 replaced. Tires
must always remain on same side of vehicle. After
changing, adjust tire pressure and torque wheel nuts diagonally to 94 ft lb
(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 ½ 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 adjacent 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 cannot 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. WARNING Do
not drive with worn tires or tires showing cuts or bruises as they may lead to
sudden deflation. If you notice that tires are wearing unevenly, consult your Porsche dealer. Uneven wear may not always be due to improper wheel alignment. It can be the result of individual driving habits such as cornering at high speeds. If the tire pressure is not checked and adjusted regularly, abnormal tire wear can also occur. Tire care
WARNING
Tire
damage Regularly
check tires for imbedded material, cuts, punctures, cracks and bulges (side
wall). In
case of tire damage, where it is uncertain whether there is a break in the
ply with all its consequences or tire damage caused by thermal or mechanical
overloading due to a loss of pressure or any other prior damage, we recommend
that the tire be replaced for safety reasons. If
one faulty tire on an axis is replaced it should be noted that the difference
is tread depth on one axle must not exceed 30%. Perform
visual inspection. Parking at the curb Hard
impacts against curbs (or traffic islands) are dangerous and may cause hidden
tire damage which is not noticeable until later. (Danger of accidents at high speeds.) Tires have a memory! WARNING: If
you must drive over a curb, drive slowly and, if possible, at right
angles. Exercise care when
parking along curbs. Tire replacement
The tire makes and types specifically mentioned in your vehicle papers are binding. When changing to different tires, be sure to observe the applicable regulations in your country. If in doubt, contact your Porsche dealer or Porsche importer of your country. If
you do not use a Porsche recommended replacement tire, make sure that you
purchase your new tires from a reputable tire specialty dealer and that the
dealer complies with all manufacturers warnings for those tires. Before mounting new tires, check with your Porsche dealer about the current release status. For
tires with VR quality standard, there are currently no final standards
concerning tire strength at speeds above 210 km/h. For
this reason, only use tire makes and types tested by Porsche. Tires
should be replaced at least on one axle at a time. As a matter of principle, only tires of the same make and
type should be combined. Mixed
tires are not permissible. 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 (100-200
km). Have
new tires mounted by an expert only. 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. If
tires are fitted already mounted on their rims, the direction of rotation and
the position with respect to the wheel hub should be marked before the wheels
are removed (e.g. by making a clear mark on the stud nearest the valve). This precaution ensures that
the wheels will be remounted in the same position, thus obviating the risk of
imbalance. When
balancing light alloy wheels, use only adhesive balancing weights supplied through
the Porsche parts service. Wheels
If
you intend to use other than original equipment 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 remounting, put tires with the
most tread depth at the front.
Have tires/wheels balanced as soon as possible. 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, especially 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 125, this means it was produced in the 12th week of
1985. 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 restrictions. Radial
ply M+S tires should be inflated with the same cold tire inflation pressures
required for the regular radial ply tires. However, do not exceed the maximum tire inflation pressure
listed on the tire sidewall. Snow
tires should have the same load capacity as original equipment tires and
should be mounted on all four wheels.
Snow tires with studs should be run at moderate speeds when new in
order to give the studs time to settle. If
tires are fitted already mounted on their rims, the direction of rotation and
position with respect to the wheel hub should be marked before the wheels are
removed (e.g. by making a clear mark on the stud nearest the valve). This precaution ensures that the
wheels will be remounted in the same position, thus obviating the risk of
imbalance. WARNING Tires
with badly worn treads and studs are very dangerous. Make sure they are replaced
immediately. Do
not drive a vehicle equipped with snow tires at prolonged high speed. Snow tires do not have the same
degree of traction on dry, wet or snowfree roads as a normal tire. Furthermore, snow tires wear rapidly
under these conditions. Snow
tires do not fulfill their purpose if the tread depth is less than 5/32 in/5
mm. Comply with all state and
local laws governing snow tire and tread depth requirements. Snow chains
Should snow chains be necessary, they must be mounted on the drive wheels only. Check
with local authorities for possible restrictions. Use
only snow chains with fine pitch links, so that enough space remains between
the chains and the inside of the wheel arches. Drive
wheels must rotate freely with chains mounted to prevent damage to body, axle
or brake components. Follow
instructions issued by the supplier of the chains. Remove chains as soon as roads are free of ice and snow. 205
/ 55 R 16 88 Q M+S
The
European tire manufacturers have changed their tire identification system for
SR and HR-tires pertaining to maximum permissible speed and maximum load carrying
capacity for belted tires. The
following is an example only. During
the transition period some tires might show both old and new identification
codes, such as 205/55 SR 16 88 Q M+S. In this instance, the new codes apply. The
identification codes for VR tires remain unchanged; for example 245/45 VR
16. (V=maximum permissible speed
for radial tires, i.e. over 130 mph or 210 km/h). |
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