2009 PORSCHE 911 service

Practical Tips, Emergency Service
243
Snow chains
Caution!
Risk of damage to body, axle or brake com-
ponents.
fFit snow chains only to the rear wheels, and
only with the tire/rim combination listed in the
Technical Data.
To ensure adequate clearance between chain
and body, Porsche recommends only the use
of fine-link chains such as those approved by
Porsche.
fFollow instructions issued by the supplier of the chains.
Different states and countries have varying statu-
tory requirements regarding maximum speed.
Check with local authorities for possible restric-
tions.
fRemove chains as soon as the roads are free
of ice and snow. 911 Carrera, 911 Carrera S
Fitting snow chains
The use of snow chains is not permitted when
5 mm spacers are mounted.
Caution!
Risk of damage to the wheel housings if the
5 mm spacers are not removed before fitting
snow chains.
fTo permit the fitting of snow chains, have the 5 mm spacers removed on all 4 wheels.
fTo fit/remove the spacers:
Please consult an authorized Porsche dealer.
fPlease see the chapter “SPACERS 911
CARRERA, 911 CARRERA S” on Page 255.
Tire designations Due to new speed and load ratings for radial tires,
new designations have come into force for snow
tires for your Porsche.
The designation to be used for ZR tires is e.g.,
265/40 ZR 18 (Z = code letter for radial tires for
speeds above 150 mph / 240 km/h).

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Practical Tips, Emergency Service
Example of InscriptionInscription on radial tireATire size
Example: P 295/30 ZR 19 100 Y
–P - The tire is designed for Passenger vehicle.
This information is not included on all tires.
–295 - Indication of tire width in mm
–30 - Indication of tire height to tire width ratio
in percent–ZR - code letter for radial tires for speeds
above 150 mph / 240 km/h
There are currently no standards concerning
tire strength at speeds above 150 mph
(240 km/h).
–R - Belt type code letter for radial
–19 - Indication of rim diameter in inches
–100 - Load capacity coefficient
–Y - Speed code letter
–XL (Extra Load) - Tire with increased load rat-
ing
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 manufacturer’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
0204, the tire was produced in the 2nd 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
pressure.

Practical Tips, Emergency Service
245
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.Speed code letterThe speed code letter indicates the maximum per-
missible speed for the tire.
This code letter is shown on the tire sidewall.Tip on driving
Tires with a maximum speed rating that is lower
than the specified maximum vehicle speed may be
mounted only if they bear an M+S identification on
the tire sidewall.
fPlease note that in addition to the winter tires,
all-season and all-terrain tires are also subject
to speed limits and bear this identification.
Inscription on light alloy wheelsMaintenance note
fProtect the valve inserts against soiling with
valve caps.
Use only plastic valve caps.
Soiled valve inserts can cause a gradual loss
of air.
Note on operation
fThe rim width in inches A and the rim offset F
are visible from the outside.
The information is inscribed on the back of the
spokes near the tire valve.
A- Rim width in inches
B- Rim-flange contour code letter
C- Symbol for drop-center rim
D- Rim diameter in inches
E-Double hump
F- Rim offset in mm
T= up to 118 mph (190 km/h)
H= up to 131 mph (210 km/h)
V= up to 150 mph (240 km/h)
W= up to 167 mph (270 km/h)
Y= up to 186 mph (300 km/h)
(Y)= up to 186 mph (300 km/h) as for
Y tires. Speeds of more than
300 km/h (186 mph) are also
possible at a maximum tire load
capacity of 85 % (confirmation from
tire manufacturer required for
speeds of more than 186 mph (300
km/h)).

246
Practical Tips, Emergency Service
Loading InformationDefinitionsThe Curb weight - actual weight of your vehicle -
vehicle weight including standard and optional
equipment, fluids and emergency tools. This
weight does not include passengers and cargo.
The Gross Vehicle Weight is sum of the curb
weight and the weight of passengers and cargo
combined.
The Gross Vehicle Weight Rating is the maxi-
mum total weight of vehicle, passengers, luggage
and optional equipment.
The Gross Axle Weight Rating is the maximum
load limit for the front or the rear axle. This infor-
mation is located on the safety compliance sticker
located in the driver’s side door jamb.
For determining the compatibility of the tire and
vehicle load capabilities:
fPlease see the chapter “TECHNICAL DATA” on
Page 286.
The load capacity coefficient (e.g. “100”) is a min-
imum requirement.The Gross Combined Weight Rating is the
maximum total weight rating of vehicle, passen-
gers and cargo.
The Vehicle Capacity Weight - Load Limit - is
the maximum total weight limit specified of the
load (passengers and cargo) for the vehicle. This
is the maximum weight of passengers and cargo
that can be loaded into the vehicle. This informa-
tion can be found on the tire pressure plate.
The maximum loaded vehicle weight is the
sum of curb weight, accessory weight, vehicle ca-
pacity weight and production options weight.
The load rating is the maximum load that a tire
is rated to carry for a given inflation pressure.
The maximum load rating is the load rating for
a tire at the maximum permissble inflation pres-
sure.
The cargo capacity is the permissible weight of
cargo, the substracted weight of passengers from
the load limit.
fNever exceed the permissible limits.
Danger!
Risk of loss of control, damage to the vehicle
and serious personal injury or death.
fNever exceed the specified axle loads.
Overloading can shorten the service life of the
tires and car, as well as lead to dangerous
vehicle reactions and long braking distances.
Damage due to overloading is not covered by the vehicle warranty.

Practical Tips, Emergency Service
247
Example for determining the combined weight of
occupants and cargoVehicle Load CapacityfThe combined weight of occupants and cargo
should never exceed the weight shown on the
tire plate in the vehicle.
Please see the chapter “TIRE PRESSURE PLA-
TE” on Page 285.
fNever exceed the number of passengers
shown on the tire pressure plate in the vehicle.Determining the combined weight of
occupants and cargo:
fAdd the weight of all occupants and then add
the total luggage weight (figure).
Steps for determining correct load limit
1. Locate the statement "The combined weight of
occupants and cargo should never exceed XXX
pounds" on your vehicle’s placard (depending
on the date of manufacture).
2. Determine the combined weight of the driver
and passengers that will be riding in your vehi-
cle.
3. Subtract the combined weight of the driver and
passengers from XXX kilograms or XXX
pounds.
4. The resulting figure equals the available
amount of cargo and luggage load capacity.
For example, if the "XXX" amount equals 1400
lbs. and there will be five - 150 lb passengers
in your vehicle, the amount of available cargo
and luggage load capacity is 650 lbs. (1400 -
750 (5 x 150) = 650 lbs.)
5. Determine the combined weight of luggage
and cargo being loaded on the vehicle. That
weight may not safely exceed the available car-
go and luggage load capacity calculated in
Step 4.

248
Practical Tips, Emergency Service
Wheel Bolts
Danger!
Risk of wheel bolt breakage and wheel sepa-
ration, resulting in serious personal injury or
death.
fFollow all instructions concerning wheel bolts. fAlways clean the wheel bolts before fitting.
fApply a thin coat of Optimoly TA (aluminum
paste) on the thread and between the bolt head
and movable spherical cap ring (arrows).
The bearing surface of the spherical cap
facing the wheel must not be greased.
fReplace damaged wheel bolts.
Only use the Original Porsche wheel bolts spe-
cially designed for this vehicle type.
Tightening torque Tightening torque of wheel bolts:
96 ftlb./130 Nm
Wheel Securing Bolts If the wheels have to be removed at the workshop,
please do not forget to hand over the wrench
socket for the wheel securing bolts along with the
car key.
The wrench socket for the wheel securing bolts is
in the tool box.
To loosen or tighten the wheel bolt with anti-theft
protection, a wrench socket with the appropriate
coding must be used between the wheel bolt and
the wheel-bolt spanner.
fWhen positioning the wrench socket, ensure
that it engages fully in the teeth of the wheel
bolt.

Practical Tips, Emergency Service
249
Changing a wheel
Warning!
Risk of serious personal injury or death. The
car may slip off the jack.
fMake sure that no one is in the vehicle when
jacking up and changing a wheel.
fAlways place the car on stable supports if work
has to be carried out under the car.
Risk of damage to the brake discs of the
Porsche Ceramic Composite Brake (PCCB).
fAlways screw in both assembly aids when changing a wheel.
Note
The tools required for changing a wheel (e.g. jack,
wheel bolt wrench, assembly aids) are not sup-
plied with the car.
Your authorized Porsche dealer will be pleased to
advise you.1. Apply the handbrake fully and engage 1st gear
or PDK selector-lever position P and remove
the ignition key.
2. Switch on the hazard warning lights if neces-
sary.
3. Secure the car against rolling away, e.g. by
means of wedges under the wheels on the op-
posite side.
This is particularly important on slopes.
4. Slightly slacken the wheel bolts of the wheel to
be changed.
5. Lift the car only at the specified jacking points.
6. Raise the car until the wheel lifts off the
ground.
Please see the chapter “LIFTING THE VEHICLE
WITH A LIFTING PLATFORM OR GARAGE LIFT”
on Page 254.
7. Remove 1 or 2 wheel bolts (see respective
illustration).
8. Screw in assembly aids instead of the wheel
bolts.
Screw in assembly aid for vehicles without Porsche
Ceramic Composite Brake9. Remove the remaining wheel bolts.
Note on operation
fTo remove or mount the spacers:
Please see the chapter “SPACERS 911
CARRERA, 911 CARRERA S” on Page 255.

250
Practical Tips, Emergency Service
Screw in two assembly aids for vehicles with Porsche
Ceramic Composite Brake10.Take the wheel off and put a new wheel on.
Please see the chapter “WHEEL BOLTS” on
Page 248.
11.Insert wheel bolts and tighten by hand.
12.Remove assembly aids, screw in remaining
wheel bolts.
Initially tighten bolts only slightly in diagonally
opposite sequence so that the wheel
is centred.13.Inflate the tire if necessary.
Please see the chapter “TIRE PRESSURES FOR
COLD TIRES (68 °F / 20 °C)” on Page 289.
14.Lower the car fully and remove the jack.
15.Tighten wheel bolts in diagonally opposite
sequence.
fImmediately after changing a wheel, use
a torque wrench to check the prescribed
tightening torque (96 ftlb./130 Nm).
Note on operation for vehicles with
Tire Pressure Monitoring
fOn vehicles with Tire Pressure Monitoring, the
settings on the on-board computer must be
updated after the wheel change.
fPlease see the chapter “TPM TIRE PRESSURE
MONITORING” on Page 143.
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 permissble tire pressure.
This information can be found on the tire pres-
sure plate or in the chapter Technical Data.
Please see the chapter “TIRE PRESSURES FOR
COLD TIRES (68 °F / 20 °C)” on Page 289.
4. Remove the pressure gage.
fPlease see the chapter “TPM TIRE PRESSURE
MONITORING” on Page 143.