2004 PORSCHE CAYENNE tire type

Driving and Driving Safety
189
Engine Braking Support
(Assistance when heading downhill)The Porsche Down-Hill Assistant is an assistance
system which helps the driver at slower downhill
driving up to approx. 12 mph (20 km/h), e.g., on
steep slopes or on wintry mountain roads.
As long as the gas pedal is not used when
traveling downhill, the Porsche Down-Hill Assistant
is active and brakes the vehicle.
If road grip is lost on one or more wheels, the
system brakes the wheels which have good road
contact.
The braking ability of the Engine Braking Support
is affected by slippery surfaces (e.g., on icy or
loose surfaces), like all brakes.
Warning!
Risk of accident, resulting in serious perso-
nal injury or death. Reduced braking ability
on a slippery surface.
fAlways adjust your driving style to the driving situation.
Conditions:
– The gas pedal must not be used when
travelling downhill.
– The speed must not exceed 12 mph
(20 km/h).–Vehicles with Tiptronic S:
The Tiptronic selector lever position D, M or R
must be engaged.
–Vehicles with manual transmission:
The reverse gear or any other gear (1. - 6. )
must be engaged. The clutch pedal must not
be used when travelling downhill.
Tip on driving
The Porsche Down-Hill Assistant is active when
driving downhill either forwards or backwards.
Checks on test standsBrake tests
Brake tests must be carried out only in High Range
and on plate-type test stands or roller test stands.
The following limit values must not be exceeded
on roller test stands:
– Testing speed 4.7 mph (7.5 km/h)
– Test duration 20 seconds
Parking brake test
Parking brake tests on the brake tester must be
performed only with the ignition switched off and
the Tiptronic selector lever in position N or the
gearshift lever in neutral.Balancing wheels on the vehicle
During finish balancing of the wheels, the entire
vehicle must be lifted and the wheels must be free
to turn.
Dynamometer testing procedure Some U.S. states and Canadian provinces con-
duct emissions inspection/maintenance testing
involving the use of two-wheel dynamometer.
A two-wheeled dynamometer is a treadmill type
device upon which a single axle of the car, the dri-
ving axle of the vehicle, rotates to simulate vehicle
operation on the road while the vehicle remains
stationary.
Your Porsche Cayenne has a full-time four-wheel
drive system which cannot be disabled. Severe
d a m a g e t o t h e p o w e r t r a i n c a n re s u l t i f t e s t e d o n a
two-wheel dynamometer.
Warning!
To avoid severe powertrain damage and a
possible unexpected movement of the vehic-
le.
fYour Porsche Cayenne vehicle must never be
tested on a two-wheel dynamometer.
fAdvise the emission station of this warning before testing the vehicle.
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285
Tire lifeTire life depends on various factors, i.e., road sur-
faces, traffic and weather conditions, driving
habits, type of tires and tire care.
fInspect your tires for wear and damage before
driving off. If you notice uneven or substantial
wear, wheels might need alignment or tires
should be balanced or replaced.Tire wearThe original equipment tires on your Porsche have
built-in tire 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 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.
Danger!
Driving on worn tires can result in loss of con-
trol of the vehicle and could cause serious
personal injuries or death.
fDo not drive with worn tires or tires showing
cuts or bruises as they may lead to sudden
deflation and loss of control which could cause
severe personal injury.
fSpecialized high performance tires on high
performance sport utility vehicles exhibit more
wear than those on a family sedan, or even a
high performance sedan.
Therefore, it is important to check your tire
pressure and condition at least every two weeks.
fIf 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 carefAvoid damaging tires and wheel rims.
fIf you must drive over a curb or other obstacle,
drive slowly and at an obtuse angle.
fCheck tires for uneven wear and damage
before driving off.
fRemove imbedded material.
fReplace worn or damaged tires immediately.
fKeep oil, fuel, brake fluid, etc. away from tires.
fReplace missing valve stem caps.
fKeep tires inflated correctly.
fWash tires when washing the vehicle. Also
clean inner side of wheels.
fDo not use abrasive cleaners when washing
the wheels.
fCheck wheel rims for corrosion.
fRemove road salt, if driving in winter.
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Minor Repairs
Tire damage, puncturefPlease see the chapter “HIGH-PRESSURE
CLEANING EQUIPMENT, STEAM CLEANERS”
on Page 271.
Danger!
Risk of serious personal injury or death.
Driving the vehicle with low tire pressure
increases risk of a tire failure and resulting
loss of control. Furthermore, low tire pres-
sure increases rate of wear of the affected
tires.
fCheck tires – including sidewalls – regularly for
foreign bodies, nicks, cuts, cracks and bulges.
fAfter driving off road, examine tires for signs
of damage such as cuts, tears, bulges or
foreign objects stuck in the tread. Replace a
damaged tire if necessary.
fCross curb edges slowly and at right angles if
possible.
Avoid driving over steep or sharp curbs.
fIn cases of doubt, have the wheel (particularly
the inner side) checked by an authorized Porsche dealer.In case of tire damage, where it is uncertain
whether there is a break in the ply with all its con-
sequences or tire damage caused by thermal or
mechanical overloading due to loss of pressure or
any other prior damage, we recommend that the
tire be replaced for safety reasons.
I f o n e f a u l t y t i re i s re p l a c e d i t s h o u l d b e n o t e d t h a t
the difference in tread depth on one axle must not
exceed 30%. Handling inconsistencies may result.
fPerform a visual inspection if necessary.
Tire replacementsfUse only tire makes and types tested by
Porsche.
If you do not use a Porsche recommended
replacement tire, make sure that you
purchase your new tires from a reputable tire
dealer and that the dealer complies with all
manufacturers warnings for those tires.
Only tires with the same manufacturer and
with the same specification code (e.g. “N0”,
“N1”...) should be mounted on the vehicle.
Before mounting new tires, check with your
Porsche dealer about the current release
status.
Tires should be replaced no less than on one axle
at the time. Only tires of the same make and type
must be used. Mixed tires are not permissible and
will affect vehicle performance, safety, and can
affect vehicle warranty.Porsche dealers can recommend the most current
replacement tire options for your vehicle.
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).
Tires must always remain on the same side of
the vehicle.
When wheels are removed, the direction of rota-
tion and position of each wheel should be marked.
If new tires are installed only on one axle, a notice-
able change in handling occurs due to the different
tread depth of the other tires. This happens espe-
cially if only rear tires are replaced. However, this
condition disappears as the new tires are broken
in.
fPlease adjust your driving style accordingly.
Installation of new tires should only be done by a
qualified tire technician.
Valves
fUse only plastic valve caps.
fThe rubber valves must be replaced whenever
the tires are changed.
fThe fitting and replacement specifications
must be observed for metal valves.
fOnly use Original Porsche metal valves.
fProtect the valve inserts against soiling with
valve caps.
Soiled valve inserts can cause a gradual loss
of air.
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Minor Repairs
Example of InscriptionInscription on radial tireATire size
Example: P 255/55R18 109 Y
–P - The tire is designed for Passenger vehicle.
This information is not included on all tires.
–255 - Indication of tire width in mm
–55 - Indication of tire height to tire width ratio
in percent
–R - Belt type code letter for radial–18 - Indication of rim diameter in inches
–109 - Load capacity coefficient
–Y - Speed code letter
–XL (Extra Load) - Tire with increased load
rating
B TIN (Tire Identification Number)
Example: DOT xx xx xxxx xxxx
–DOT
The DOT symbol indicates that the tires com-
ply with the requirements of the US Depart-
ment of Transportation and provides informa-
tion about:
– first two-digit code means manufacture’s iden-
tification mark.
– second two-digit code means tire size.
– third four-digit code means tire type code.
– fourth four-digit code means date of manufac-
ture.
If, for example, the last four numbers read
1204, the tire was produced in the 12th week
of 2004.
C Tire ply composition and material
The number of layers in the tread and sidewalls
and their material composition.
D Maximum permissible inflation pressure
The maximum permissible cold inflation pressure
to which a tire can be inflated.
fDo not exceed the permissible inflation pres-
sure.
E Maximum Load rating
The maximum load in kilograms and pounds can
be carried by the tire. If you replace tires always
use a tire that has the same maximum load rating
as the factory installed tire.
FRadial
The identification indicates if the tire has radial
structure.
G Term of tubeless or tube tire
Identification for tubeless tires.
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293
SpacersfUse the spacers only together with wheels
approved by Porsche.
Before having spacers fitted, find out about the
current approval status.
fRemove spacers if 18 inch tires, snow chains
or a collapsible spare wheel are mounted.
Danger!
Risk of accident if the spacers are not
removed before mounting 18 inch tires or
collapsible spare wheel.
f17 mm spacers are always to be removed
before mounting 18 inch tires or a collapsible
spare wheel, because the wheel cannot be fit-ted correctly. Caution!
Risk of damage to wheel housings if the
spacers on the rear axle are not removed
before fitting the snow chains.
f17 mm spacers must always be removed from the rear axle when snow chains are to be fitted.Note on operation
fTo remove or mount the spacers:
Please see the chapter “CHANGING A WHEEL
WITH REMOVAL OF 17 MM SPACER” on
Page 303.
Please see the chapter “FITTING THE 17 MM
SPACER” on Page 305.
Wheel BoltsfAlways clean the wheel bolts before installing.
Maintenance Notes
fWheel bolts must not be greased.
fReplace damaged wheel bolts.
Only use the original Porsche wheel bolts
specially designed for this vehicle type.
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303
Screw in two assembly aids on vehicles with PCCB3. Remove the remaining wheel bolts.
For more information on wheel bolts:
Please see the chapter “WHEEL BOLTS” on
Page 293.
4. Change wheel.5. Insert wheel bolts and tighten by hand. Remo-
ve assembly aids and screw in remaining
wheel bolt.
Initially tighten bolts in diagonally opposite se-
quence so that the wheel is centered.
6. Inflate the tire if necessary.
Please see the chapter “TIRE PRESSURES,
COLD (68 °F/20 °C)” on Page 354.
In vehicles with tire pressure monitoring:
Please see the chapter “SETTING THE TIRE
TYPE AND SIZE” on Page 134.
7. Lower car and remove jack.
8. Tighten wheel bolts in diagonally opposite se-
quence.
Tire Pressure Monitoring:
The settings on the multi-purpose display must be
updated after a wheel change.
fPlease see the chapter “SETTING TIRE PRES-
SURE MONITORING” on Page 132.
Maintenance Note
fImmediately after changing a wheel, use
a torque wrench to check the prescribed
tightening torque of the wheel bolts
(118 ftlb./160 Nm).
Changing a wheel with removal of 17 mm
spacer
Danger!
Risk of accident if the spacers are not
removed before mounting 18 inch tires or
collapsible spare wheel.
f17 mm spacers are always to be removed
before mounting 18 inch tires or a collapsible
spare wheel, because the wheel cannot be fitted correctly. Caution!
Risk of damage to wheel housings if the
spacers on the rear axle are not removed be-
fore fitting the snow chains.
f17 mm spacers must always be removed from the rear axle when snow chains are to be fitted.
fRemove spacers if 18 inch tires, snow chains
or a collapsible spare wheel are mounted.
fIt is not necessary to use a assembly aid for
mounting a wheel or spare wheel of the same
quality.
fFor information on the spacers: Please see the
chapter “SPACERS” on Page 293.
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305
8. Inflate the tire if necessary.
Please see the chapter “TIRE PRESSURES,
COLD (68 °F/20 °C)” on Page 354.
On vehicles with Tire Pressure Monitoring:
Please see the chapter “SETTING THE TIRE
TYPE AND SIZE” on Page 134.
9. Lower the car and remove the jack.
10.Tighten wheel bolts in diagonally opposite
sequence.
Maintenance Note
fImmediately after changing a wheel, use
a torque wrench to check the prescribed
tightening torque of the wheel bolts
(160 Nm/118 ftlb.).
fSpacer, steel nuts, and plastic covers should
be stored together.
Fitting the 17 mm spacer1. Remove wheel.
2. Fit the spacer with the wheel bolts A used to
fasten the wheel.
Tightening torque: 160 Nm (118 ftlb.)
3. Fit wheel.
To d o t h i s use the original wheel nuts for
fastening the wheels.
Tightening torque: 160 Nm (118 ftlb.)
Place plastic covers onto the steel nuts.
Note
There is no anti-theft protection for the wheel nuts.Collapsible spare wheelThe collapsible spare wheel is fastened under the
floor in the luggage compartment.
On vehicles with 17 mm spacers:
fBefore fitting a collapsible spare wheel on the
rear axle always remove the corresponding
spacer.
For information on the spacers:
Please see the chapter “SPACERS” on
Page 293.
For information about removing the spacers:
Please see the chapter “CHANGING A WHEEL
WITH REMOVAL OF 17 MM SPACER” on
Page 303.1. Take out rotary knob A and put it on bolt B.
2. Unscrew the screw and take out the collapsible
spare wheel.
3. Mount the collapsible spare wheel on the vehi-
cle before inflating it. Leave the car jacked up.
Please see the chapter “LIFTING THE VEHICLE
WITH A JACK” on Page 299.
4. Inflate the tire.
Please see the chapter “TIRE PRESSURES,
COLD (68 °F/20 °C)” on Page 354.
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Warning!
Risk of accident.
fThe collapsible spare wheel must be used only
over short distances in cases of emergency.
For safety reasons, replace the tires before
the wear indicators appear (webs in the tire
grooves, 1/16 in. (1.6 mm) high).
fNever deactivate the Porsche Stability
Management (PSM) system.
fAvoid hard acceleration and high cornering
speeds.
The maximum permitted speed is 50 mph
(80 km/h) and must not be exceeded
because of altered driving characteristics and
for reasons of wear.
The tread depth of the spare wheel is subject
to the same laws as the original tires.
fDo not use a collapsible spare wheel from a
different vehicle type.
fDo not mount the collapsible spare wheel from
your car on a different vehicle.
fOnly fit one collapsible spare wheel on the
vehicle at a time.
fOn vehicles with air suspension, use the tire fil-
ling connection A only to inflate the collapsible
spare wheel.
fTo avoid damage, do not use automatic car washes when the spare wheel is installed.After using the collapsible spare wheel
fRelease air by unscrewing the valve insert.
Notes on operation
The tire will revert to its original shape only after
several hours. Only then can it be stowed in the
spare wheel recess in the luggage compartment.
There is a plastic sheet in the tool box to store the
damaged wheel.
Maintenance Note
The collapsible spare wheel must be repaired only
by the manufacturer.
fPlease consult your authorized Porsche dealer
if the collapsible spare wheel is defective.
Checking tire pressure with a pressure
gage1. Remove the valve stem cap from the tire.
2. Press the pressure gage onto the valve stem.
Note on operation
fDo not press too hard or force the valve stem
sideways, or air will escape.
If the sound of air escaping from the tire is
heard, reposition the pressure gage.
3. Read the tire pressure on the gage stem and
compare it to the permissible tire pressure.
This information can be found on the tire pres-
sure plate in the left door aperture.
Please see the chapter “TIRE PRESSURES,
COLD (68 °F/20 °C)” on Page 354.
4. Remove the pressure gage.
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