2005 PORSCHE 911 CARRERA Owners Manual

Practical Tips, Emergency Service
217
Wheel alignment, wheel balancing As a precaution, have wheels with summer tires
balanced in the spring, and those with mud and
snow tires before winter.
Unbalanced wheels may affect car handling and
tire life.
Only the specified weights may be used for wheel
balancing.
Self-adhesive weights must not come into contact
with cleaning agents, since they could drop off.
Uneven tread wear indicates wheel imbalance. In
this event, the vehicle should be checked at an au-
thorized Porsche dealer.
Warning!
If, during a journey, uneven running or vibra-
tions occur that could be caused by damage
to tires or the car, the speed must be re-
duced immediately, but without braking
sharply.
If you continue your trip without having the
cause of the fault remedied, you might lose
control of your vehicle which could cause se-
vere personal injury.
fStop the vehicle and check the tires.
fIf no cause for the fault can be found, drive
carefully to the nearest authorized Porsche dealer.
Removing and storing tires fAfter changing, adjust tire pressure and torque
wheel bolts diagonally to 94 ftlb (130 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 preception that tire durability and perform-
ance are immune to the effects of storage and
age is unfounded.
Chemical additives, which make the rubber elas-
tic, 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 num-
bers read 1204, then the tire was produced in the
12th week of 2004.
fStore tires in a cool and dry place.

218
Practical Tips, Emergency Service
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.
Danger!
Risk of accident and serious personal injury
or death due to excessive speed.
fAlways check the maximum speed rating on
the tire sidewall on any tire on the vehicle.
fNever exceed the maximum speed rating of the tires.
fFit winter tires to both axles well before the
cold season begins.
Your authorized Porsche dealer will be pleased
to advise you.
Maintenance note
We recommend fitting winter tires on the vehicle at
temperatures below 45°F (7°C ).
Winter tires lose their traction capability when their
tread depth falls below 5/32 in. (4 mm).

Practical Tips, Emergency Service
219
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.
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).

220
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 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
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 pres-
sure.

Practical Tips, Emergency Service
221
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.
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)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. This information
can be found 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

222
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 observe the chapter “TIRES, RIMS,
TRACKS” on Page 266.
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 personal injury, loss of control and
damage to vehicle.
fNever exceed the specified axle loads. Over-
loading 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 vehi-cle warranty.

Practical Tips, Emergency Service
223
Example for determining the combined weight of occu-
pants and cargoVehicle Load CapacityfThe combined weight of occupants and cargo
should never exceed the weight shown on the
tire plate in the vehicle.
Please observe the chapter “TIRE PRESSURE
PLATE” on Page 263.
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.

224
Practical Tips, Emergency Service
A-Front jacking pointLifting the Vehicle with a Lifting
Platform or Garage Lift The car must be raised only at the illustrated jack-
ing points.
B-Rear jacking point
Caution!
Serious injury and/or serious damage to the
engine or the vehicle may occur, if you lift
the vehicle improperly.
fNever lift the vehicle at any other place than
the jacking points.
fNever lift the vehicle by the engine, transmis-
sion or axles.
fDo not damage any sensitive components in the vicinity of the jacking points.
Platform lift Before the car is driven on to a lifting platform, it
must be ensured that there is enough space be-
tween the lifting platform and the vehicle. Garage lift A garage lift must be used only at the illustrated
jacking points.