2009 PORSCHE 911 page 2

236
Practical Tips, Emergency Service and a half (1-1/2) times as well on the government
course as a tire graded 100.
The relative performance of tires depends upon
the actual conditions of their use, however, and
may depart significantly from the norm due to var-
iations in driving habits, service practices and dif-
ferences in road characteristics and climate.
Traction AA, A, B, C
The traction grades, from highest to lowest, are
AA, A, B, and C and they represent the tire’s ability
to stop on wet pavement as measured under con-
trolled conditions on specified government test
surfaces of asphalt and concrete.
A tire marked C may have poor traction perform-
ance.
Warning!
The traction grade assigned to this is based on
braking (straight-ahead) traction tests and does
not include cornering (turned) traction, accelera-
tion, hydroplaning or peak traction characteris-
tics.
Temperature A, B, C
The temperature grades are A (the highest), B and
C, representing the tire’s resistance to the gener-
ation of heat and its ability to dissipate heat when
tested under controlled conditions on a specified
indoor laboratory test wheel.
Sustained high temperatures can cause the mate-
rial of the tire to degenerate and reduce tire life,
and excessive temperature can lead to sudden tire failure.
The grade C corresponds to a level of perform-
ance which all passenger car tires must meet un-
der the Federal Motor Vehicle Safety Standard No.
109.
Grades B and A represent higher levels of per-
formance on the laboratory test wheel than the
minimum required by law.
Warning!
The temperature grade for this tire is established
for a tire that is properly inflated and not overload-
ed.
Excessive speed, underinflation, or excessive
loading, either separately or in combination, can
cause heat buildup and possible tire failure, result-
ing in serious personal injury or death. Tire pressures
Warning!
Incorrect tire pressure causes increased tire
wear and adversely affects road handling.
This could lead to tire failure, resulting in loss
of control, leading to serious personal injury
or death.
fAlways use an accurate tire pressure gage
when checking inflation pressures.
fDo not exceed the maximum tire pressure list-
ed on the tire sidewall.
Please see the chapter “TIRE PRESSURE PLA-
TE” on Page 285.fCold tire inflation pressure means: all tires
must be cold, ambient temperature maximum
(68 °F/20 °C)
, when adjusting the inflation
pressure.
Avoid sunlight striking the tires before measur-
ing cold pressures, since the pressures would
rise from temperature influence.
fValve caps protect the valve from dust and dirt,
and thus from leakage.
Always screw caps tightly down.
Replace missing caps immediately.
fUse only plastic valve caps.
fDo not use commercially available sealant or
tire inflating bottles. Only use Porsche
approved tire sealant.
fPlease see the chapter “TIRE PRESSURES FOR
COLD TIRES (68 °F / 20 °C)” on Page 289.

Practical Tips, Emergency Service
237
Each tire, should be checked every 2 weeks when
cold (68 °F/20 °C) and inflated to the inflation
pressure recommended in this Owner's Manual or
on the tire-pressure plate.
If your vehicle has tires of a different size than the
size indicated in this Owner's Manual or on the tire-
pressure plate, you should determine the proper
tire inflation pressure for those tires.
As an added safety feature, your vehicle has been
equipped with a tire pressure monitoring (TPM)
that illuminates a low tire pressure message when
one or more of your tires is significantly under-in-
flated. Accordingly, when the low tire pressure
message illuminates, you should stop and check
your tires as soon as possible, and inflate them to
the proper pressure. Driving on a significantly un-
der-inflated tire causes the tire to overheat and
can lead to tire failure. Under-inflation also reduc-
es fuel efficiency and tire tread life, and may affect
the vehicle’s handling and stopping ability.
Please note that the TPM is not a substitute for
proper tire maintenance, and it is the driver’s re-
sponsibility to maintain correct tire pressure, even
if under-inflation has not reached the level to trig-
ger illumination of the TPM low tire pressure mes-
sage.
fOn vehicles with tire pressure monitoring:
Please see the chapter “TPM TIRE PRESSURE
MONITORING” on Page 143.
When tires are warm, the tire pressure is
increased.fNever let air out of hot tires.
This could cause the tire pressure to fall below
the prescribed value.
Insufficient tire filling pressure can cause tires to
overheat and thus be damaged – even invisibly.
Hidden tire damage is not eliminated by subse-
quently correcting the tire pressure.
Overloading
Danger!
Risk of damage to vehicle parts, loss of con-
trol and serious personal injury or death.
fDo not overload your vehicle. Be careful about
the roof load.
fIf loading the vehicle also correct the tire pres-
sure. Tire pressure for loaded vehicle can be
found on the tire pressure plate and in the
chapter technical data.
fNever exceed the specified axle load.
Overloading can shorten the service life of the
tires and car, as well as lead to dangerous ve-
hicle reactions and long braking distances.
Damage due to overloading is not covered by the vehicle warranty.
fPlease see the chapter “LOADING INFORMA-
TION” on Page 246.
fPlease see the chapter “TIRE PRESSURES FOR
COLD TIRES (68 °F / 20 °C)” on Page 289.
Example of a tire pressure plateTire pressure plateInformation on the tire pressure plate
A Seating capacity
Maximum number of vehicle occupants, inclu-
ding the driver.

238
Practical Tips, Emergency Service B Vehicle load limit
Is the maximum total weight limit specified of
the load (passengers and cargo) for the vehi-
cle. This is the maximum weight of passengers
and cargo that can be loaded into the vehicle.
Please see the chapter “LOADING INFORMA-
TION” on Page 246.
C Tire size for the front axle
Check with your authorized Porsche dealer
about the current release status.
D Recommended tire pressure for the front axle
These values are for cold tires (68 °F/20 °C).
E Tire size for the rear axle
Check with your authorized Porsche dealer
about the current release status.
F Recommended tire pressure for the rear axle.
These values are for cold tires (68 °F/20 °C).
G In vehicles with collapsible spare wheel:
Size and tire pressure of the spare wheel.
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 “hydroplane” and may cause par-
tial or complete loss of traction, vehicle
control or stopping ability.
fReduce speed on wet surface to prevent this. Tire life Tire life depends on various factors, i. e., road
surfaces, 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 wear The 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.
Snow tires lose their traction capability when their
tread depth falls below 5/32 in. (4 mm).
In the United States, state laws may govern the
minimum tread depth permissible. Follow all such
laws.

Practical Tips, Emergency Service
239
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 sports cars 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.
If you notice that tires are wearing unevenly, con-
sult 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 fAvoid 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.
Tire damage, puncture High-pressure cleaning units can damage the
tires.
fPlease see the chapter “HIGH-PRESSURE
CLEANING UNITS, STEAM CLEANERS” on
Page 224.
fCheck tires for imbedded material, cuts, punc-
tures, cracks and bulges (side wall) before driv-
ing off.
In case of tire damage, where it is uncertain wheth-
er there is a break in the ply with all its conse-
quences or tire damage caused by thermal or me-
chanical overloading due to loss of pressure or
any other prior damage, we recommend that the
tire be replaced for safety reasons.
If one faulty tire is replaced it should be noted that
the difference in tread depth on one axle must not
exceed 30%.
Handling inconsistencies may result.
fPerform a visual inspection if necessary.

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).

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.

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.