four wheel drive PORSCHE 911 GT3 2010 5.G Owners Manual

Operation, Safety
57
ABS Brake System
(Antilock Brake System)The ABS system represents a major contribution
to the enhancement of active safety in your
vehicle. This system prevents the wheels from
locking in a panic stop on almost all road
surfaces. With the ABS system in your vehicle, the
following areas are enhanced: Steering, vehicle remains steerable under all
braking forces when ABS is engaged.
Good directional control, no swerving caused
by locking of wheels under braking conditions.
Shorter stopping distance, stopping distances
are usually reduced because controlled braking is
maximized.
Prevention of wheel lock up, no brake-induced
sliding and thus no localized tire wear from
emergency braking.
The crucial advantage of the ABS system over a
conventional brake system is in the area of
maintaining directional control and maneuverabi-
lity of the car in emergency situations.
Warning!
The increased control that is provided should
not induce you to take greater risks with your
safety. The limits dictated by the laws of
physics cannot be overcome, even with ABS.
The risk of accidents due to inappropriate
speed cannot be reduced, even by the ABS.
The driver bears the responsibility for all
driving maneuvers.
fAdapt your driving style to the prevailing road
and weather conditions.
fObey all traffic laws.
Other vehicles not equipped with the ABS
system may not be able to maintain control,
especially on wet or poor road surfaces and
thus may be more likely to impact you from
behind.
fTo minimize that risk, use your ABS system to
increase your ability to maneuver to avoid
dangerous situations and not merely to try to stop in the shortest distance possible.
Operation of the ABS systemA wheel speed sensor is mounted to each of the
four wheels. If wheel lock-up of either of the front
wheels or the rear wheels is sensed during
braking, the brake pressure is adjusted automati-
cally until the wheel no longer slips.
If braking forces approach the wheel lock-up point
for all wheels (panic braking) the ABS system will
intervene to provide a rapid rythmic braking. The
proper operation of ABS is perceived by the driver
as a pulsating brake pedal in conjunction with
audible noise and perhaps some vibration.
fIf you experience these sensations while
driving or a road surface with questionable
traction, reduce vehicle speed appropriate for
the prevailing road conditions.
fIf full braking should be necessary, press the
brake pedal all the way down throughout the
entire braking procedure, regardless of the
pulsating pedal. Do not ease up on pressure
applied to the pedal.
The functional readiness of all the main electrical
components of the ABS is checked by an
electronic monitoring system both before and
while you drive.
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134
Instruments, On-Board Computer
TPM
Tire Pressure MonitoringfPlease see the chapter “TIRE PRESSURES FOR
COLD TIRES 68 °F/20 °C” on Page 237.
The Tire Pressure Monitoring continuously
monitors tire pressure and tire temperature on all
four wheels and warns the driver when the tire
pressure is too low.
The display as well as the settings for the Tire
Pressure Monitoring take place on the on-board
computer.
However, you must still adjust the tire pressure on
the wheel.fThe driver is responsible for filling the tires
correctly and making the correct settings on
the on-board computer.
The Tire Pressure Monitoring offers the following
functions:
– Display of the actual tire pressure while the
vehicle is in motion.
– Display of the deviation from the required
pressure (refilling pressure).
– Display of currently set tire type.
– Tire pressure warnings in two stages.
Warning!
Despite the advantages offered by the Tire
Pressure Monitoring, it is still the driver’s
responsibility to update the corresponding
settings in the on-board computer and
maintain the pressure in the tires.
Low tire pressure reduces the road safety of
the vehicle and destroys the tire and wheel.
fWhen a flat tire has been displayed, immedia-
tely stop in a suitable place and check the tires
for damage. If necessary, remedy the damage
with a tire sealant.
fDo not by any means continue to drive with
damaged tires.
fSealing the tire with tire sealant is only an
emergency repair, so you can drive to the next
authorized Porsche dealer. The maximum
permitted speed is 50 mph (80 km/h).fDo not drive with tires whose tire pressure
drops again in a short period of time. In cases
of doubt, have tires checked by an authorized
Porsche dealer.
fDamaged tires must be immediately replaced
by an authorized Porsche dealer.
Tire repairs are not permissible under any
circumstances.
fIf a fault occurs in the Tire Pressure Monitoring
(e.g. defective wheel transmitter), contact an
authorized Porsche dealer immediately and
have the damage repaired.
The tire pressure will not be monitored at all or
will be monitored only partially by defective
Tire Pressure Monitoring.
fTires lose air over time without a tire defect
being present. A tire pressure warning will then
appear in the on-board computer display.
Correct the tire pressure at the next oppor-
tunity.
fThe Tire Pressure Monitoring gives a warning
about tire damage due to natural pressure loss
as well as about a gradual loss of pressure due
to foreign objects.
The Tire Pressure Mnitoring cannot warn you
about tire damage that occurs suddenly (e.g.
flat tire due to abrupt external effects).
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Instruments, On-Board Computer
135
Tire pressure function of the on-board
computer
The tire pressure function of the on-board
computer displays the tire pressures (actual
pressure) dependent on temperature in the four
wheels.
You can watch the tire pressure rise as the tempe-
rature increases while driving.
This display is only for information.
fUnder no circumstances should the tire
pressures be changed based on this display.
Warning!
This display is for informational purposes
only. Under no circumstances should the tire
pressures be changed based on this display.
Changing the tire pressure to incorrect
pressures could adversely affect the perfor-
mance, driving characteristics, and safety of
your vehicle.
fMaintain tire pressures according to the units
indicated on the tire pressure plate, located on the drivers side door of the vehicle.
Displaying the tire pressure function of the
on-board computer
fPush operating lever up or down until the tire
pressure function of the on-board computer
appears.
(The selection field must be switched off.)Pressure info in tire pressure menu
In accordance with physical principles, the air
pressure changes as the temperature changes.
The tire pressure increases or decreases by
around 1.5 psi (0.1 bar) for every 18 °F (10 °C)
change in temperature.
The Tire Pressure Monitoring takes this relation-
ship between tire pressure and temperature into
account.
fPlease see the chapter “PRESSURE INCREASE
AS THE RESULT OF TEMPERATURE
INCREASE” on Page 142.
You can read the tire pressures to be
corrected in this display.
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Practical Tips, Emergency Service
191
Removing and storing tires fAfter changing, adjust tire pressure and torque
wheel bolts diagonally to 370 ftlb (500 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 perfor-
mance are immune to the effects of storage and
age is unfounded.
Chemical additives, which make the rubber
elastic, 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. 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 four
numbers read 1209, then the tire was produced in
the 12th week of 2009.
fStore tires in a cool and dry place.
Snow tires For a better grip on snow and ice, use radial M+S
tires with studs.
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.
fTherefore install M+S tires before driving in such conditions. Before mounting snow tires, consult with
your Porsche dealer. He has the technical
information necessary to advise you on
wheel and tire compatibility.
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.
Danger!
Tires with badly worn treads and studs are
very dangerous and could cause accidents
resulting in serious personal injuries or
death.
fMake sure they are replaced immediately.
fDo 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.
Comply with all state and local laws
governing snow tire and tread depth require-
ments.
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