tire size Lexus GS450h 2007 Using the hands-free system (for cellular phone) / LEXUS 2007 GS450H THROUGH JUNE 2006 PROD. (OM30727U) User Guide

390
4-3. Do-it-yourself maintenance
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.

5
When trouble arises
449
5-2. Steps to take in an emergency
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 pressure 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 an d 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) malf unction 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) malfunction 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 pressure 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 and alternate tires and wheels allow the TPMS (tire pressure warning
system) to continue to function properly.

487
6-1. Specifications
6
Vehicle specifications
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, 155/70D17 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)

492
6-1. Specifications
Tire information
Ty p i c a l t i r e s y m b o l s
Tire size(P. 4 9 4 )
DOT and Tire Identification Number (TIN) ( P. 493 )
Location of tread wear indicators ( P. 3 7 5 )
Tire ply composition and materials
Plies are layers of rubber-coated parallel cords. Cords are the strands
which form the plies in a tire.
Radial tires or bias-ply tires
A radial tire has RADIAL on the sidewall. A tire not marked RADIAL is a
bias-ply tire.
TUBELESS or TUBE TYPE
A tubeless tire does not have a tube and air is directly filled in the tire. A
tube type tire has a tube inside the tire and the tube maintains the air pres -
sure.
Load limit at maximum cold tire inflation pressure ( P. 4 9 7 )
Maximum cold tire inflation pressure ( P. 4 9 7 )
This means the pressure to which a tire may be inflated.
Uniform tire quality grading
For details, see “Uniform tire quality grading” that follows.

493
6-1. Specifications
6
Vehicle specifications
Typical DOT and tire identification number (TIN)
DOT symbol*
Tire Identification Number (TIN)
Tire manufacturer's identifica -
tion mark
Tire size code
Manufacturer's optional tire
type code (3 or 4 letters)
Manufacturing week
Manufacturing year
*: The DOT symbol certifies that the tire conforms to applicable
Federal Motor Vehicle Safety
Standards.
Summer tire or all season tire (P. 380)
An all season tire has “M+S” on the sidewall. A tire not marked “M+S” is a
summer tire.

494
6-1. Specifications
Tire size
■Typical tire size information
The illustration indicates typical
tir
e 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)
■ T
ire dimensions
Section width
Ti r e h e i g h t
Wheel diameter

498
6-1. Specifications
Tire related termMeaning
Production options
weight
The combined weight of installed regular production
options weighing over 5 lb. (2.3 kg) in excess of the
standard items which they replace, not previously
considered in curb weight or accessory weight,
including heavy duty brakes, ride levelers, roof rack,
heavy duty battery, and special trim
Vehicle capacity weight
(Total load capacity)The rated cargo and luggage load plus 150 lb. (68
kg) times the vehicle's designated seating capacity
Intended outboard side-
wall
(a) The sidewall that contains a whitewall, bears white lettering, or bear s manufacturer, brand,
and/or model name molding that is higher or
deeper than the same molding on the other side-
wall of the tire, or
(b) The outward facing sidewall of asymmetrical tire that has a particular side that must always face
outward when mounted on a vehicle
Occupant distributionDistribution of occupants in a vehicle as specified in
the third column of Table 1
* below
Recommended inflation
pressureCold tire inflation pressure recommended by a man-
ufacturer.
RimA metal support for a tire or a tire and tube assembly
upon which the tire beads are seated
Rim diameter 
(Wheel diameter)Nominal diameter of the bead seat
Rim size designationRim diameter and width
Rim type designationThe industry manufacturer's designation for a rim by
style or code
Rim widthNominal distance between rim flanges

505
6
Vehicle specifications
6-3. Initialization
Items to initialize
ItemWhen to initializeReference
Pow e r w i n d ow
• After reconnecting or changing the battery
• After changing a fuse
P. 5 3
Moon roofP. 5 6
Variable gear ratio
steeringP. 1 5 1
Intuitive parking assistP. 1 5 1
Engine oil maintenance
data• After changing engine oilP. 3 6 6
Tire pressure warning
system
• When rotating the tires on vehicles differing with front and rear tire infla-
tion pressures.
• When changing the tire inflation pressure by changing traveling speed
or load weight, etc.
• When changing the tire size.
P. 3 7 7
After reconnecting or performing main tenance on the 12 volt battery, the
hybrid system may not start. (
 P. 3 7 2 ) Also, the following items must be
initialized for normal system operation.

516
Alphabetical index
Hybrid vehicle immobilizer 
system ..................................................... 62
Theft prevention labels .......................... 66
Tire inflation pressure ......................... 487
Tire information Glossary................................................. 497
Size ........................................................... 494
Tire identification number ............. 493
Uniform tire quality grading ......... 495
Tires Chains ....................................................... 176
Checking ............................................... 375
Compact spare tire .......................... 457
If you have a flat tire ............. 455, 456
Inflation pressure................................ 487
Information............................................ 492
Pressure warning system .............. 375
Replacing ............................................... 456
Rotating tires ........................................ 375
Size ........................................................... 487
Snow tires ................................................ 177
Tools ........................................................... 456
Total load capacity ................................ 173
Touch screen ........................................... 182
Towing Dinghy towing ...................................... 180
Emergency towing ............................. 421
Trailer towing......................................... 179
TRAC (Traction control) .................... 162
Transmission If the shift lever cannot be 
shifted from P ................................... 467
Mode select switch............................ 105
S mode..................................................... 106
Transmission ......................................... 104
Trip meter .................................................... 111Trunk
Opener ..................................................... 30
Trunk light ................................................. 32
Wattage ................................................. 488
Turn signal lights Replacing light bulbs ......................... 413
Switch ........................................................ 108
Wattage ................................................. 488
Vanity lights Vanity lights............................................ 318
Wattage ................................................. 488
Vanity mirrors ..........
...................................318
VDIM (Vehicle Dynamics 
Integrated Management) ................163
Vehicle identification number.......... 481
Vehicle load limits .................................. 173
Ventilators ............................................... 326
VGRS (Variable Gear Ratio 
Steering) .................................................162
VSC (Vehicle Stability Control) ...... 162
Warning buzzers Brake system ....................................... 430
Downshifting.......................................... 106
Open door ........................................... 432
Seat belt reminder ............................ 433
Warning lights Anti-lock brake system (ABS) .... 432
Brake system ....................................... 430
Charging system ................................. 431
ECB/VSC (Electronically 
Controlled Brake System/ 
Vehicle Stability Control)...........432
V
W