2008 Lexus GS450h wheel size

450
4-3. Do-it-yourself maintenance
GS_HV_U
December 27, 2007 1:38 pm
■When replacing wheels
The wheels of your Lexus are equipped with tire pressure warning valves and trans-
mitters that allow the tire pressure warning system to provide advanced warning in
the event of a loss in tire inflation pressure. Whenever wheels are replaced, the tire
pressure warning valves and transmitters must be installed. ( P. 4 3 6 )
CAUTION
■When replacing wheels
●Do not use wheels that are a different size from those recommended in the
Owner’s Manual, as this may result in loss of handling control.
●Never use an inner tube in a leaking wheel which is designed for a tubeless tire.
Doing so may result in an accident, causing death or serious injury.
NOTICE
■Replacing tire pressure warning valves and transmitters
●Because tire repair or replacement may affect the tire pressure warning valves
and transmitters, make sure to have tires serviced by your Lexus dealer or other
qualified service shop. In addition, make sure to purchase your tire pressure
warning valves and transmitters at your Lexus dealer.
●Ensure that only genuine Lexus wheels are used on your vehicle. 
Tire pressure warning valves and transmitters may not work properly with non-
genuine wheels.

498
5-2. Steps to take in an emergency
GS_HV_U
December 12, 2007 3:50 pm
CAUTION
■Maintenance of the tires
Each tire, including the spare (if provided), should be checked monthly when cold
and inflated to the inflation pressure re commended by the vehicle manufacturer on
the vehicle placard or tire inflation pressu re label (tire and load information label).
(If your vehicle has tires of a different size than the size indicated on the vehicle
placard or tire inflation pressure label [tire and load information label], 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 system (TPMS-tire pressure warning system) that illuminates a low tire
pressure telltale (tire pressure warning light) when one or more of your tires is sig-
nificantly under-inflated. Accordingly, when the low tire pressure telltale (tire pres-
sure warning light) illuminates, you should stop and check your tires as soon as
possible, and inflate them to the proper pressure. Driving on a significantly under-
inflated tire causes the tire to overheat and can lead to tire failure. Under-inflation
also reduces fuel efficiency and tire tread life, and may affect the vehicle’s handling
and stopping ability.
Please note that the TPMS (tire pressure warning system) is not a substitute for
proper tire maintenance, and it is the driver’s responsibility to maintain correct tire
pressure, even if under-inflation has not reached the level to trigger illumination of
the TPMS low tire pressure telltale (tire pressure warning light).
Your vehicle has also been equipped with a TPMS (tire pressure warning system)
malfunction indicator to indicate when th e system is not operating properly. The
TPMS (tire pressure warning system) malfunction indicator is combined with the
low tire pressure telltale (tire pressure warning light). When the system detects a
malfunction, the telltale will flash for approximately one minute and then remain
continuously illuminated. This sequence will continue upon subsequent vehicle
start-ups as long as the malfunction exists . When the malfunction indicator is illumi-
nated, the system may not be able to detect or signal low tire pressure as intended.
TPMS (tire pressure warning system) malfunctions may occur for a variety of rea-
sons, including the installation of replacem ent or alternate tires or wheels on the
vehicle that prevent the TPMS (tire pres sure warning system) from functioning
properly. Always check the TPMS (tire pressure warning system) malfunction tell-
tale after replacing one or more tires or wheels on your vehicle to ensure that the
replacement or alternate tires and wheels allow the TPMS (tire pressure warning
system) to continue to function properly.

551
6-1. Specifications
6
Vehicle specifications
GS_HV_U
December 12, 2007 3:50 pm
Steering
Tires and wheels
Free playLess than 1.2 in. (30 mm)
Ti r e s i z e245/40R18 93Y, P245/40R18 93V, 
245/40ZR18, T155/70D17 110M (spare)
Front and rear tire inflation 
pressure
(Recommended cold tire inflation
pressure)
Driving under normal conditions
35 psi (240 kPa, 2.4 kgf/cm2 or bar)
Driving at high speeds above 100 mph (160
km/h) (in countries where such speeds are per-
mitted by law) Add 9 psi (60 kPa, 0.6 kgf/cm
2 or bar) to the
front tires and rear tires. Never exceed the
maximum cold tire inflation pressure indicated
on the tire sidewall.
Spare tire inflation pressure 
(Recommended cold tire inflation
pressure)
60 psi (420 kPa, 4.2 kgf/cm2 or bar)
Wheel size18  8 J, 17  4T (spare)
Wheel nut torque76 ft•lbf (103 N•m, 10.5 kgf•m)

559
6-1. Specifications
6
Vehicle specifications
GS_HV_U
December 12, 2007 3:50 pm
Tire size■ Typical tire size information
The illustration indicates typical
tire size.
Ti r e u s e 
(P = Passenger car, 
T = Temporary use)
Section width (millimeters)
Aspect ratio 
(tire height to section width)
Tire construction code 
(R = Radial, D = Diagonal)
Wheel diameter (inches)
Load index (2 or 3 digits)
Speed symbol 
(alphabet with one letter)
■ Tire dimensions
Section width
Ti r e h e i g h t
Wheel diameter

590
Alphabetical index
GS_HV_U
December 12, 2007 3:50 pm
Smart access system with 
push-button start Antenna location....................................37
Entry function.......................................... 35
Starting the 
hybrid system .................................... 138
Spare tire Inflation pressure................................. 551
Spare tire................................................. 518
Spark plug ............................................... 548
Specifications .........................................544
Speedometer........................................... 148
Steering wheel Adjustment................................................73
Audio switches ...................................303
Steering wheel position 
memory.................................................. 60
Storage compartment ........................359
Storage feature......................................355
Stuck If your vehicle becomes stuck.......541
Sun visors ................................................. 362
Switch Fog light switch ...................................... 161
Ignition switch....................................... 138
Light switches ....................................... 158
Mode select switch............................. 143
Power door lock switch .................... 50
“POWER” switch ............................... 138
Power window switch ......................... 77
Tire pressure warning 
reset switch ....................................... 436
Tire pressure 
warning select switch...................438
Window lock switch ............................ 77
Wipers and washer switch ............. 162 Tachometer ............................................. 148
Tail lights
Switch ........................................................158
Theft deterrent system Alarm.......................................................... 90
Immobilizer system ............................. 88
Theft prevention labels.......................... 92
Tire inflation pressure .......................... 551
Tire information Glossary ................................................ 562
Size ........................................................... 559
Tire identification number .............558
Uniform Tire Quality Grading ... 560
Tires Chains....................................................... 216
Checking............................................... 435
Compact spare tire............................518
If you have a flat tire ............... 517, 527
Inflation pressure ................................. 551
Information ........................................... 556
Replacing ................................................ 517
Rotating tires........................................ 435
Size ............................................................. 551
Snow tires................................................ 218
Tire pressure warning system..... 435
Tools.............................................................517
Total load capacity ................................. 214
Touch screen.......................................... 224
Towing Dinghy towing .......................................221
Emergency towing ........................... 482
Trailer towing ...................................... 220
Traction control.....................................200T