tire pressure PORSCHE 911 GT3 2004 5.G Owners Manual

TIre Pressures forCold TIres

Summer tiresandsnow tires

Front
Rear
32
psi (2.2 bar)overpressure
39 psi (2.7 bar)overpressure

These tirepressures arevalid onlyforPorsche approved tires.
For replacement tiresitis imperative thatyouconsult theTechnical DataandTires, Wheels
sections ofthis manual andfollow therecommendations containedtherein.

5

Operation ofthe ABS system
A wheel speed sensor ismounted toeach ofthe
four wheels. Ifwheel lock-up ofeither ofthe front
wheels orthe rear wheels issensed duringbrak-
ing, thebrake pressure isadjusted automatically
until thewheel nolonger slips.Thebrake pressure
is regulated foreach frontwheel individually and
for both ofthe rear wheels together.
On aroad surface whichisslippery ononly one
side, therear wheel whichisbraking onthe slip-
pery surface determines thebrake pressure which
will beapplied equallytoboth rearwheels. Thisen-
sures thatdirectional stabilityismaintained. How-
ever, ifbraking forcesapproach thewheel lock-up
point forallwheels (panicbraking) theABS system
will intervene toprovide arapid rythmic braking.
The proper operation ofABS isperceived bythe
driver asapulsating brakepedalinconjunction
with audible noiseandperhaps somevibration.

I>
Ifyou experience thesesensations whiledriv-
ing oraroad surface withquestionable trac-
tion, reduce vehicle speedappropriate forthe
prevailing roadconditions.
The functional readinessofall the main electrical
components ofthe ABS ischecked byan
electronic monitoring systembothbefore and
while youdrive. •
Warning lightUSA
• Warning lightCanada
When theignition isswitched onthe ABS warning
light willlight upwhile thesystem iselectronically
interrogated andgoes outwhen theengine is
started ifthe check isnot yetcomplete.
If the ABS warning lampfailstogo out, thisindi-
cates thatABS hasbeen deactivated duetoa
fault. Ifthe warning lightsinthe instrument panel
and on-board computer lightupwhile youaredriv-
ing, this indicates thatafault hasoccurred. Inboth
cases, normal braking, asinvehicles withoutABS,
is still retained.
The ABS system should,however, beexamined at
an authorized Porschedealerimmediately topre-
vent theoccurrence offurther faults.

I>
Ifthe ABS system becomes inoperative, take
your vehicle toyour authorized Porschedealer
immediately.
A

Warning!
The control unitofthe ABS brake system is
set forstandard tiresize. Ifnon-standard
tires areinstalled, thecontrol unitmay mis-
interpret thespeed ofthe vehicle, because of
the variant dataitreceives fromthesensors
on the axles.

I>
Use only tiremakes andtypes tested by
Porsche.
Controls,Instruments

FuelEconomy

Fuel economy willvary depending onwhere,
when andhow youdrive, optional equipment
installed, andthegeneral condition ofyour
car.
A car tuned tospecifications andcorrectly
maintained, willhelp youtoachieve optimal
fuel economy.

~ Have yourvehicle tunedtospecifications.
Air cleaner shouldbedirt free toallow proper
engine "breathing".
Battery shouldbefully charged.
Wheels shouldbeproperly aligned.
Tires should beinflated atcorrect pressure.
~ Always monitor yourfuelconsumption.
~ Drive smoothly, avoidabrupt changes inspeed
as much aspossible.
~ Avoid jackrabbit startsandsudden stops.
~ Donot drive longer thannecessary inthe lower
gears. Shifting intoahigher gearearly without
lugging theengine willhelp save fuel.
~ Prolonged "warmup"idling wastes gas.Start
the vehicle justbefore youareready todrive.
Accelerate slowlyandsmoothly.
~ Switch offthe engine ifstationary forlonger
periods.
Maintenance, CarCare ~
Any additional weightcarried inthe vehicle re-
duces fueleconomy. Alwayskeepcargo toa
minimum andremove allunnecessary items.
~ Organize yourtripstotake inseveral errands
in one trip.
~ Allelectrical accessories contributetoin-
creased fuelconsumption.
~ Only switch onthe airconditioning whenneces-
sary.
~ Donot drive withtheRoof Transport System
mounted unlessyouneed it.

The EPA estimated m.p.g.isto be used for
comparison purposes,actualmileage may
be different fromtheestimated m.p.g.,
depending onyour driving speed,weather
conditions andtriplength. Youractual
highway mileagewillprobably beless than
the estimated m.p.g.

~ Please observe alllocal andnational speed
limits.
Operating
YourPorsche inother
Countries

Government regulationsinthe United States and
Canada requirethatautomobiles meetspecific
emission regulations andsafety standards. There-
fore, carsbuiltforthe U.S. andCanada differfrom
vehicles soldinother countries.
If you plan totake your Porsche outsidetheconti-
nentallimits ofthe United States orCanada, there
is the possibility that
- unleaded fuelmay notbeavailable;
- unleaded fuelmay have aconsiderably lower
octane rating.Excessive engineknockandse-
rious damage toboth engine andcatalytic con-
verters couldresult;
- service maybeinadequate duetolack ofprop-
er service facilities, toolsordiagnostic equip-
ment;
- replacement partsmaynotbeavailable orvery
difficult toget.

Porsche cannotberesponsible forthe
mechanical damagethatcould result
because ofinadequate fuel,service orparts
availability.

If you purchased yourPorsche abroadandwant to
bring itback home, besure tofind outabout ship-
ping andforwarding requirements, aswell ascur-
rent import andcustoms regulations.

Washing

The best method ofprotecting yourcarfrom the
damaging effectsofthe environment isfrequent
washing andtheapplication ofapreservative. The
underside ofyour vehicle shouldalsobewashed
thoroughly, atthe latest whensaltisno longer
spread onthe roads.
The longer salt,road dustandindustrial dust,
dead insects, birddroppings orsubstances from
trees (resin, pollen) areallowed toremain onthe
bodywork, themore serious istheir harmful ef-
fect.
New cars should bewashed carefully withplenty
of clear water toprotect thenew paint work. Dark
paint finishes showupthe smallest ofsurface
damage (e.g.,scratches) morereadily thanlighter
colors.
Dark colors arealso more susceptible toscratch-
ing because ofthe composition oftheir pigments
and require particularly carefulpaintcare.

D-
Donot wash yourcarinbright sunlight orwhile
the bodywork isstill hot.

D-
When washing byhand, useabundant water,a
soft sponge orwash brush, andPorsche car
shampoo.

D-
Begin byspraying thebody thoroughly withwa-
ter torinse away loose dirt.
D-

After washing, rinsethecarwith plenty ofwa-
ter and then drywith achamois leather.
Do not use thesame chamois leatherfordry-
ing asyou useforcleaning thewindshield and
windows.

/!\
Warning!
Moisture whichgetsontothe brakes during
a car wash canreduce braking efficiency or
make thebrakes pullunevenly whichcould
increase thedanger ofan accident, causing
serious personal injuriesordeath.

D-
Always applythebrakes afew times after
washing thecartotest braking efficiency and
dry the brake discs.
When doingthis,take care nottohamper other
road users behind you(traffic conditions per-
mitting),

Automatic carwashes

Optional add-onpartsorparts which project
beyond thecontours ofthe vehicle maybe
damaged bydesign features (e.g.brushes) ofau-
tomatic carwashes.
The
following partsareparticularly
susceptible todamage:

- Windshield wipers(always switchthemoffto
prevent themwiping unintentionally inintermit-
tent operation)
- External telephone antennas(alwaysunscrew)
- Roof Transport System(alwaysremove com-
pletely)
- Rear spoiler
- Wheels (thewider therimand thelower thetire
height, thegreater therisk ofdamage)
- High-gloss wheels(toprevent thesefromget-
ting scratched, donot clean withthewheel-
cleaning brushesofthe carwash).

D-
Please consult theoperator beforeusingauto-
matic carwashes.

D-
Wash anddrybyhand allpoints notreached by
a car wash, suchasdoor andlidseams or
door sills.

Note

Automatic carwashes spraywater atodd angles
and high pressures, whicharenotseen innormal
driving. Therefore, watercansometimes findits
way intothepassengers compartment duringor
shortly afterthecarwash.

D-D- D-

Maintenance, CarCare

Storing yourPorsche

If you intend tostore yourPorsche foraprolonged
period, pleaseconsult yourauthorized Porsche
dealer. Thestaff willbeglad toadvise youonthe
most suitable andnecessary methods.
r> Clean yourvehicle thoroughly insideandout-
side.
Clean theengine compartment.
The under carriage andchassis components
should befree ofdirt and saltdeposits.
r> Fillupthe fuel tank.
r> Change theoiland oilfilter, andrunthe engine
for several minutes.
r>

Increase thetire pressure to58 psi (4bar).
It is not recommended tolift the vehicle, dueto
the possibility ofcorrosion onshock absorber
piston shafts.
The vehicle shouldbemoved slightly, approxi-
mately everyfourweeks, toprevent flatspot
on the tires.

Climate control

The airconditioning systemshouldbeingood
working condition andfully charged.

WindshieldjHeadlight washer

r> Check andcorrect antifreeze/cleaning solu-
tion level asnecessary.

Electrical system

r> Remove thebattery fromthevehicle andstore
it in acool dryplace, notonacement floor.

When thebattery isdisconnected, the
alarm system isdeactivated.

r> Recharge thebattery every3months. Ifthe
battery remains inthe vehicle withthecables
connected, itis necessary tocheck, remove
and recharge thebattery every2-3weeks.

Do not fast charge thebattery.

r> Please observe thechapter "SATTERY" on
Page 155.
Vehicle
interior

The interior mustbedry, especially inthe area of
the floor carpets. Theuseofdrying agents (Silica-
Gel) isrecommended invehicles withleather inte-
rior and inareas withhighhumidity. Therecom-
mended amountis3fabric bagsof1.1 Ibs.
(500 grams) eachplaced onthe floor carpets.
Windows, doorsandlidsmust beclosed. Theair
flaps should beopened.
Maintenance, CarCare

Temperature A,8,C

The temperature gradesareA(the highest), Band
C, representing thetire's resistance tothe gener-
ation ofheat anditsability todissipate heatwhen
tested undercontrolled conditions onaspecified
indoor laboratory testwheel.
Sustained hightemperatures cancause themate-
rial ofthe tire todegenerate andreduce tirelife,
and excessive temperature canlead tosudden
tire failure.
The grade Ccorresponds toalevel ofperfor-
mance whichallpassenger cartires must meet
under theFederal MotorVehicle SafetyStandard

No. 109.

Grades Band Arepresent higherlevelsofperfor-
mance onthe laboratory testwheel thanthemini-
mum required bylaw.

A
Warning!

The temperature gradeforthis tireisestablished
for atire that isproperly inflatedandnotoverload-

ed.

Excessive speed,underinflation, orexcessive
loading, eitherseparately orincombination, can
cause heatbuildup andpossible tirefailure.
Tire
pressures

A
Warning!
Incorrect tirepressure causesincreased tire
wear andadversely affectsroadhandling.

I>
Always useanaccurate tirepressure gauge
when checking inflationpressures.

I>
Donot exceed themaximum tirepressure list-
ed onthe tire sidewall.
Please observe thechapter "VEHICLE IDENTI-
FICATION, TECHNICAL DATA"onPage 179.

I>
Cold tireinflation pressure means:alltires
must becold, ambient temperature maximum
68°F (20°C), whenadjusting theinflation pres-
sure.
Avoid sunlight strikingthetires before measur-
ing cold pressures, sincethepressures would
rise from temperature influence.

I>
Valve capsprotect thevalve fromdustand
dirt, andthus from leakage.
Always screwcapstightly down.
Replace missingcapsimmediately.

I>
Donot use commercially availablesealantor
tire inflating bottles.
Tire
traction

A
Warning!
When driving onwet orslushy roads,a
wedge ofwater maybuild upbetween the
tires andtheroad. Thisphenomenon is
known as"hydroplane" andmay cause par-
tial orcomplete lossoftraction, vehicle
control orstopping ability.
I>
Reduce speedonwet surface toprevent this.

Tire life

Tire lifedepends onvarious factors, i.e., road
surfaces, trafficandweather conditions, driving
habits, typeoftires andtirecare.

I>
Inspect yourtires forwear anddamage before
driving off.Ifyou notice uneven orsubstantial
wear, wheels mightneedalignment ortires
should bebalanced orreplaced.
Practical Tips,Emergency Service

Tirewear

The original equipment tiresonyour Porsche have
built-in tirewear indicators. Theyaremolded into
the bottom ofthe tread grooves andwillappear as
approximately 1/2in(12 mm) bands whenthetire
tread depth isdown to1/16 ofan in(1.6 mm).
When theindicators appearintwo ormore adja-
cent grooves, itis time toreplace thetires. We
recommend, however,thatyoudonot letthe tires
wear down tothis extent.
Worn tirescannot griptheroad surface properly
and areeven lesseffective onwet roads.
In the United States, statelawsmaygovern the
minimum treaddepth permissible. Followallsuch
laws.
PracticalTips,Emergency Service
/!\

Warning!
Driving onworn tirescanresult inloss of
control ofthe vehicle andcould cause severe
personal injuries.

0>
Donot drive withworn tiresortires showing
cuts orbruises asthey mayleadtosudden
deflation andloss ofcontrol whichcouldcause
severe personal injury.

0>
Specialized highperformance tiresonhigh
performance sportscarsexhibit morewear
than those onafamily sedan, oreven ahigh
performance sedan.
Therefore, itis important tocheck yourtire
pressure andcondition atleast every two
weeks.
If you notice thattires arewearing unevenly, con-
sult your Porsche dealer.
Uneven wearmaynotalways bedue toimproper
wheel alignment. Itcan bethe result ofindividual
driving habitssuchascornering athigh speeds. If
the tire pressure isnot checked andadjusted
regularly, abnormal tirewear canalso occur.
Tire
care

0>
Avoid damaging tiresandwheel rims.

0>
Ifyou must driveoveracurb orother obstacle,
drive slowly andatan obtuse angle.

0>
Check tiresforuneven wearanddamage
before driving off.

0>
Remove imbedded material.

0>
Replace wornordamaged tiresimmediately.

0>
Keep oil,fuel, brake fluid,etc.away fromtires.

0>
Replace missingvalvestemcaps.

0>
Keep tiresinflated correctly.

Tiredamage, puncture

t>
Check tiresforimbedded material,cuts,punc-
tures, cracks andbulges (sidewall)before
driving off.
In case oftire damage, whereitis uncertain
whether thereisabreak inthe plywith allits con-
sequences ortire damage causedbythermal or
mechanical overloading duetoloss ofpressure or
any other priordamage, werecommend thatthe
tire bereplaced forsafety reasons.
If one faulty tireisreplaced itshould benoted that
the difference intread depth onone axle must not
exceed 30
%.

Handling inconsistencies mayresult.

t>
Perform avisual inspection ifnecessary.
Tire replacements
If in doubt, contact yourPorsche dealeror
Porsche Importer ofyour country.
Use only tiremakes andtypes tested byPorsche.

If you donot use aPorsche recommended
replacement tire,make surethatyou
purchase yournewtires from areputable
tire dealer andthat thedealer complies with
all manufacturers warningsforthose tires.
Only tires withthesame make andwith the
same specification code(e.g."NO", "Nl"... )
can bemounted. Before
mounting newtires, check withyour
Porsche dealeraboutthecurrent release
status.
Use tires with"ZR" quality standards.
There
are currently nostandards concerning tire
strength atspeeds above150mph (240 kmjh).
Tires should bereplaced noless than onone axle
at the time.
Only tires ofthe same makeandtype must be
used. Mixed tiresarenotpermissible.
Initially, newtires donot have theirfulltraction.
You should therefore driveatmoderate speeds
during thefirst 60-120 miles (100-200 km).
If new tires areinstalled onlyonone axle, anotice-
able change inhandling occursduetothe different
tread depth ofthe other tires.
This happens especially ifonly reartires arere-
placed. However, thiscondition disappears asthe
new tires arebroken in.

t>
Please adjustyourdriving styleaccordingly.
Installation ofnew tires should onlybedone bya
qualified tiretechnician.
Valves

Rubber valvestems mustbereplaced everytime
a tire isreplaced.
For metal valves, theinstallation andreplacement
instructions mustbeobserved.
Use only genuine Porsche metalvalves.
Parking atthe curb

/!\
Warning!
Hard impacts againstcurbs(ortraffic
islands) aredangerous andmay cause hid-
den tiredamage whichisnot noticeable until
later. Suchdamage canresult inaccidents
at high speeds causing severepersonal inju-

ry.

Depending onthe force ofimpact, theedge
of the rim can also bedamaged.

t>
Ifyou areindoubt, havethewheel checked by
an expert, particularly ifyou suspect damage
on the inside.

I>
Ifyou must driveoveracurb orother obstacle,
drive slowly andatan obtuse angle.Exercise
care when parking alongcurbs.
Practical Tips,Emergency Service

Wheelalignment, wheelbalancing

As aprecaution, havewheels withsummer tires
balanced
in
the spring, andthose withmud and
snow tiresbefore winter.
Unbalanced wheelsmayaffect carhandling and
tire life.
Only thespecified weightsmaybeused forwheel
balancing. Self-adhesive weightsmustnotcome intocontact
with cleaning agents,sincetheycould dropoff.
A wheel should always bebalanced afteratire re-
pair.
Uneven treadwearindicates wheelimbalance. In
this event, thevehicle shouldbechecked atan au-
thorized Porschedealer.

/!\.
Warning!
If, during ajourney, unevenrunning orvibra-
tions occur thatcould becaused bydamage
to tires orthe car, thespeed mustbere-
duced immediately, butwithout braking
sharply.
If you continue yourtripwithout havingthe
cause ofthe fault remedied, youmight lose
control ofyour vehicle whichcouldcause se-
vere personal injury.

c>
Stop thevehicle andcheck thetires.

c>
Ifno cause forthe fault canbefound, drive
carefully tothe nearest authorized Porsche
dealer.
Practical Tips,Emergency Service
Removing
andstoring tires

c>
After changing, adjusttirepressure andtorque
wheel boltsdiagonally to94 ftlb (130 Nm).
Please observe thechapter "CHANGING A
WHEEL" onPage 150.

Tires mustalways remain onthe same side
of the vehicle.

When wheels areremoved, thedirection ofrota-
tion andposition ofeach wheel should bemarked.

Example

FR (front right), FL,RRand RL.
Wheels mustalways befitted inaccordance with
their marking.
The preception thattiredurability andperfor-
mance areimmune tothe effects ofstorage and
age isunfounded.
Chemical additives, whichmaketherubber elas-
tic, lose their effectiveness inthe course oftime
and therubber becomes brittleandcracks.

Therefore, thetires should beinspected
from timetotime. Note

Under nocircumstances shouldtiresolder than6
years beused onyour Porsche.
The ageofthe tire can beobtained fromthe"DOT"
code number. If,for example, thelast four num-
bers read 1203, thenthetire was produced inthe
12th week of2003.

c>
Store tiresinacool anddryplace.

Snow tires

For abetter griponsnow andice,useradial M+S
tires withstuds.
Check withyour local Motor Vehicle Bureaufor
possible restrictions.

/!\.
Warning!
Risk ofloss ofcontrol anddamage tothe
vehicle aswell assevere personal injury.
The standard tiresprofile andrubber mix-
ture areoptimized forwet and drydriving
conditions, andmay notprove favorable for
snow conditions.

c>
Therefore installM+Stiresbefore driving in
such conditions.

Flat
lire
j!\ Warning!
Failure tofollow theseinstructions mayre-
sult inserious personal injuriestoyou orto
bystanders.

~ Ifyou have aflat tire, move asafe distance off
the road. Turntheemergency flasheronand
use other warning devicestoalert other motor-
ists. Settheparking brake.
~ Donot park your vehicle whereitmay contact
dry grass, brushorother flammable materials.
The hotparts ofthe exaust system couldset
such materials onfire, thereby causing both
property damageandsevere orfatal physical
injury.
~ Set upawarning triangleatasuitable
distance.
A tire repair kit,compressor andpressure tester
are located undertheluggage compartment floor.
~ Please observe thesafety andoperating in-
structions onthe special sealant bottlewitha
special Porsche partnumber andonthe com-
pressor -these areessential.
Important
note
Sealing thetire with thetire repair kitisonly
an emergency repair.Evenwiththetire air-
tight, itmay beused onlyforshort journeys
in an emergency.
The maximum permittedspeedis50 mph
(80 kmjh).

~ Donot use commercially availablesealantor
tire inflating bottles.

j!\Warning! Risk ofaccident.

~ Have tiresreplaced byaspecialist workshop
as soon aspossible.
~ Avoid hardacceleration andhigh cornering
speeds.
PracticalTips,Emergency Service