tire size PORSCHE BOXSTER 2005 2.G Owners Manual

56
Controls, Instruments
Operation of the ABS system A wheel speed sensor is mounted to each of the
four wheels. If wheel lock-up of either of the front
wheels or the rear wheels is sensed during bra-
king, the brake pressure is adjusted automatically
until the wheel no longer slips. The brake pressure
is regulated for each front wheel individually and
for both of the rear wheels together.
On a road surface which is slippery on only one si-
de, the rear wheel which is braking on the slippery
surface determines the brake pressure which will
be applied equally to both rear wheels. This ensu-
res that directional stability is maintained. Howe-
ver, if braking forces approach the wheel lock-up
point for all wheels (panic braking) the ABS system
will intervene to provide a rapid rythmic braking.
The proper operation of ABS is perceived by the
driver as a pulsating brake pedal in conjunction
with audible noise and perhaps some vibration.
fIf you experience these sensations while dri-
ving or a road surface with questionable trac-
tion, reduce vehicle speed appropriate for the
prevailing road conditions.
The functional readiness of all the main electrical
components of the ABS is checked by an electro-
nic monitoring system both before and while you
drive. When the ignition is switched on the ABS warning
light will light up while the system is electronically
interrogated and goes out when the engine is star-
ted if the check is not yet complete.
If the ABS warning lamp fails to go out, this indica-
tes that ABS has been deactivated due to a fault.
If the warning lights in the instrument panel and on-
board computer light up while you are driving, this
indicates that a fault has occurred. In both cases,
normal braking, as in vehicles without ABS, is still
retained.
The ABS system should, however, be examined at
an authorized Porsche dealer immediately to pre-
vent the occurrence of further faults.
fIf the ABS system becomes inoperative, take
your vehicle to your authorized Porsche dealer
immediately.
Warning!
The control unit of the ABS brake system is
set for standard tire size. If non-standard ti-
res are installed, the control unit may misin-
terpret the speed of the vehicle, because of
the variant data it receives from the sensors
on the axles.
fUse only tire makes and types tested by Porsche.
Warning light USA
Warning light Canada

Practical Tips, Emergency Service
207
Example of a tire pressure plate ATire pressure plateDepending on when your vehicle was manufac-
tured, the tire pressure plate in the left door aper-
ture will contain different data.
Information on the tire pressure plate A
A Seating capacity
Maximum number of vehicle occupants, includ-
ing the driver.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.
If a trailer is being towed, the trailer tongue
weight must be included as part of the cargo
load.
Please observe the chapter “LOADING INFOR-
MATION” on Page 216.
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.
Example of a tire pressure plate BInformation on the tire pressure plate B
A Information for tire sealant, seating capacity,
vehicle load limit
B Approved tire size for the front axle
C Permissible tire pressure for the front axle
D Tire pressure for fully loaded or partially
loaded vehicle
E Permissible tire pressure for the rear axle
F Approved tire size for the rear axle

214
Practical Tips, Emergency Service
Example of InscriptionInscription on radial tireATire size
Example: P 265/40 ZR 18 101 Y
–P - The tire is designed for Passenger vehicle.
This information is not included on all tires.
–265 - Indication of tire width in mm
–40 - 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
–18 - Indication of rim diameter in inches
–101 - 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.

Vehicle Identification, Technical Data
263
fWhen changing tires or fitting new ones: Please observe the chapter “WHEEL BOLTS” on Page 222.
Danger!
Installation of sizes not authorized by
Porsche may have a dangerous effect on
the driving stability and could result in
severe personal injury or death.
fBefore mounting new tires, check with yourPorsche dealer about the current release status. Boxster S Tires Rim Rim offset Track
Summer tiresfront 235/40 ZR 18 91Y 8 J x 18 H2 57 mm 58.5 in./1486 mm
rear 265/40 ZR 18 101Y XL 9 J x 18 H2 43 mm 60.2 in./1528 mm
or front 235/35 ZR 19 87Y 8 J x 19 H2 57 mm 58.5 in./1486 mm
rear 265/35 ZR 19 94Y 9.5 J x 19 H2 46+ mm 60.0 in./1522 mm
Snow tiresfront 255/40 R 18 91V M+S 8 J x 18 H2 57 mm 58.5 in./1486 mm
rear * 255/40 R 18 95V M+S 9 J x 18 H2 43 mm 60.2 in./1528 mm
The load capacity coefficient (e.g. “91”) and maximum speed code letter (e.g. “Y”) are minimum requirements.
Tire and rim sizes
Extensive tests are performed before specific tires and wheels are approved by Porsche. Your Porsche dealer has information
about approved tires and wheels and is happy to assist you. If aftermarket tires and/or wheels are installed which are not
approved by Porsche, the vehicle’s roadability and handling characteristics might be impaired. Since Porsche has no data on
such combinations, Porsche cannot stand behind the safety or durability of these aftermarket combinations.
* Snow chains Can be mounted only on the rear wheels; maximum speed 30 mph/50 km/h. Use only Porsche authorized fine-link
cross-type or edge chains. Snow chain clearance can be guaranteed only with the tire + rim combination marked.

Index
275
RRadiator fans .............................................. 171
Radio reception .......................................... 139
Rain sensor ................................................ 110
Range on remaining fuel ........................87
, 100
Rear fog light .....................................108, 249
Rear lid ...................................................... 132
Rear spoiler............................................62, 63
Rear view mirrors ......................................... 31
Rear window defogger.................................. 33
Rear wing
Retractable........................................... 62
Relays ........................................................ 226
Release button ........................................... 147
Remote control ............................................. 18
Replacement key .......................................... 17
Replacing bulbs .......................................... 239
Replacing wiper blades................................ 169
Retractable spoiler........................................ 62
Rims
Diameter ............................................ 215
Rim width ........................................... 215
Running in .................................................... 14
SSafety belts ..........................................42
, 199
Warning light ........................................ 43
Safety compliance sticker ........................... 258
Sealing set ................................................. 220
Seals, care of ............................................. 197
Seat ............................................................ 34
Adjustment ........................................... 34
Heating ................................................ 38Memory................................................36
Selector lever .............................................147
Selector lever position indicator ............ 81
, 149
Shifting gear ...............................................146
Shiftlock .....................................................147
Side lights ..................................................249
Side marker light ............................... 108, 248
Side vents ..................................................120
Snow chains .............................. 213
, 263
, 264
Snow tires ......................................... 212, 262
Sockets .....................................................124
Spare key .....................................................17
Spare wheel ...............................................264
Speed code letter .......................................214
Speed control .............................. 76
, 113
, 114
Speed limit .......................................... 88, 214
Speedometer................................................78
Spoiler .........................................................62
Fixed ....................................................63
Retractable ...........................................62
Sport mode ..................................... 57
, 60, 61
Sports seat ..................................................34
Stability management system (PSM) ...............58
Starting ................................................. 67, 68
Starting and stopping the engine ....................67
Steering wheel
Adjustment ...........................................39
Buttons ................................................40
Lock ................................. 67
, 68, 69, 70
Rocker switches..................................147
Toggle switches ..................................147
Stopwatch ....................................................92
Storage options ..........................................126
Storing your Porsche..................................200
Sun visors ....................................................41Switching passenger’s airbag on and off ........ 48
TTachometer ................................................. 79
Tail light ..................................................... 249
Tank .................................................. 178
, 179
cap ................................................... 179
Ventilation system.............................. 184
Telephone .................................................. 141
Temperature setting........................... 114, 117
Temperature, outside indicator ...................... 83
Test stand, measurements ............................ 60
Theft protection ........................................... 16
Tiptronic .................................................... 147
Indicator .............................................. 81
Tires ................................... 14
, 203
, 262
, 263
Checking pressure............................. 223
Inscription .......................................... 214
Loading information ............................ 216
Pressure................................ 5
, 206
, 263
Pressure plate.................................... 259
Sealant .............................................. 220
Sidewall ............................................. 214
Size .................................................. 214
Tires and tire care ...................................... 203
Tools ......................................................... 136
Towing .............................................. 254, 255
Track ........................................................ 262
Transmission ............................. 145
, 146
, 261
Fluid .......................................... 190, 266
Trunk entrapment ....................................... 132
Turn signals ......................................... 79, 109

276UUndercoating ............................. 182
, 196
, 197
VValves ........................................................ 210
Vanity mirror................................................. 41
Vehicle
Care .................................................. 191
Identifikation label............................... 258
Identifikation number ........................... 258
Laying up the car................................ 231
Putting into operation .......................... 232
Washing ............................................. 191
Ventilation .................................................. 117
Vents .................................................114
, 117
Viscosity, engine oil.................................... 174
WWarning messages ..................................... 102
Washer fluid .......................................184
, 266
Washer lever .............................................. 110
Washing ..................................................... 191
Weights...................................................... 267
Welcome Home Function............................. 108
Wheel ............................... 198
, 203
, 262
, 263
Bolts ............................................17, 222
Changing............................................ 224
Checking pressure..........................5, 223
Inscription .......................................... 214
Loading information............................ 216
Pressure plate .................................... 259
Sidewall ............................................. 214Size ................................................... 214
Tire pressure ................................. 5
, 206
Tire sealant ........................................ 220
Windows ............................... 25
, 28, 154
, 196
Washer nozzles................................... 110
Washer system .......................... 184, 266
Windshield wipers .............................. 110, 169
Replacing ........................................... 169
Windstop .................................................... 161
Winter driving
Battery ............................................... 230
Jump lead starting.............................. 236
Winter operation
Coolant .............................................. 170
Locks................................................. 193
Seals ................................................. 197
Snow chains ....................................... 213
Tires .................................................. 212
Washer fluid........................................ 184
Wiper blades....................................... 169