2008 Lexus GS450h inflation pressure

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)

557
6-1. Specifications
6
Vehicle specifications
GS_HV_U
December 12, 2007 3:50 pm
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. 5 6 2 )
Maximum cold tire inflation pressure ( P. 5 6 2 )
This means the pressure to which a tire may be inflated.
Uniform tire quality grading
For details, see “Uniform Tire Quality Grading” that follows.
Summer tire or all season tire (P. 440)
An all season tire has “M+S” on the si dewall. A tire not marked “M+S” is a
summer tire.
“TEMPORARY USE ONLY”
A compact spare tire is identified by the phrase “TEMPORARY USE
ONLY” molded into its sidewall. This tire is designed for temporary emer-
gency use only.

562
6-1. Specifications
GS_HV_U
December 12, 2007 3:50 pm
■Temperature A, B, C
The temperature grades are A (the highest), B, and C, representing
the tire’s resistance to the generation of heat and its ability to dissipate
heat when tested under controlled conditions on a specified indoor
laboratory test wheel.
Sustained high temperature can cause the material of the tire to degenerate
and reduce tire life, and excessive temperature can lead to sudden tire fail-
ure.
The grade C corresponds to a level of performance which all passenger car
tires must meet under the Federal Mo tor Vehicle Safety Standard No. 109.
Grades B and A represent higher levels of performance on the laboratory
test wheel than the minimum required by law.
Warning: The temperature grades for this tire are established for a tire that
is properly inflated and not overloaded. 
Excessive speed, underinflation, or excess ive loading, either separately or in
combination, can cause heat buildup and possible tire failure.
Glossary of tire terminology
Tire related termMeaning
Cold tire inflation pres-
sureTire pressure when the vehicle has been parked for
three hours or more, or has not been driven more
than 1 mile or 1.5 km under that condition
Maximum inflation pres-
sureThe maximum cold inflated pressure to which a tire
may be inflated, shown on the sidewall of the tire
Recommended inflation
pressureCold tire inflation pressure recommended by a man-
ufacturer

565
6-1. Specifications
6
Vehicle specifications
GS_HV_U
December 12, 2007 3:50 pm
Tire related termMeaning
ChunkingThe breaking away of pieces of the tread or sidewall
CordThe strands forming the plies in the tire
Cord separationThe parting of cords from adjacent rubber com-
pounds
CrackingAny parting within the tread, sidewall, or innerliner of
the tire extending to cord material
CT
A pneumatic tire with an inverted flange tire and rim
system in which the rim is designed with rim flanges
pointed radially inward and the tire is designed to fit
on the underside of the rim in a manner that encloses
the rim flanges inside the air cavity of the tire
Extra load tire
A tire designed to operate at higher loads and at
higher inflation pressures than the corresponding
standard tire
GrooveThe space between two adjacent tread ribs
InnerlinerThe layer(s) forming the inside surface of a tubeless
tire that contains the inflating medium within the tire
Innerliner separationThe parting of the innerliner from cord material in the
carcass
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

566
6-1. Specifications
GS_HV_U
December 12, 2007 3:50 pm
Tire related termMeaning
Light truck (LT) tire
A tire designated by its manufacturer as primarily
intended for use on lightweight trucks or multipur-
pose passenger vehicles
Load ratingThe maximum load that a tire is rated to carry for a
given inflation pressure
Maximum load ratingThe load rating for a tire at the maximum permissible
inflation pressure for that tire
Maximum permissible
inflation pressureThe maximum cold inflation pressure to which a tire
may be inflated
Measuring rimThe rim on which a tire is fitted for physical dimension
requirements
Open spliceAny parting at any junction of tread, sidewall, or
innerliner that extends to cord material
Outer diameterThe overall diameter of an inflated new tire
Overall width
The linear distance between the exteriors of the side-
walls of an inflated tire, including elevations due to
labeling, decorations, or protective bands or ribs
Passenger car tire
A tire intended for use on passenger cars, multipur-
pose passenger vehicles, and trucks, that have a
gross vehicle weight rating (GVWR) of 10,000 lb. or
less
PlyA layer of rubber-coated parallel cords
Ply separationA parting of rubber comp ound between adjacent
plies

567
6-1. Specifications
6
Vehicle specifications
GS_HV_U
December 12, 2007 3:50 pm
Tire related termMeaning
Pneumatic tire
A mechanical device made of rubber, chemicals, fab-
ric and steel or other materials, that, when mounted
on an automotive wheel, provides the traction and
contains the gas or fluid that sustains the load
Radial ply tire
A pneumatic tire in which the ply cords that extend to
the beads are laid at substantially 90 degrees to the
centerline of the tread
Reinforced tire
A tire designed to operate at higher loads and at
higher inflation pressures than the corresponding
standard tire
Section width
The linear distance between the exteriors of the side-
walls of an inflated tire, excluding elevations due to
labeling, decoration, or protective bands
SidewallThat portion of a tire between the tread and bead
Sidewall separationThe parting of the rubber compound from the cord
material in the sidewall
Snow tire
A tire that attains a traction index equal to or greater
than 110, compared to the ASTM E-1136 Standard
Reference Test Tire, when using the snow traction test
as described in ASTM F-1805-00, Standard Test
Method for Single Wheel Driving Traction in a
Straight Line on Snow-and Ice-Covered Surfaces,
and which is marked with an Alpine Symbol ( )
on at least one sidewall

575
6
Vehicle specifications
GS_HV_U
December 12, 2007 3:50 pm
6-3. Initialization
Items to initialize
ItemWhen to initializeReference
Intuitive parking assist
• After reconnecting or changing the battery
• After changing a fuse
P. 5 1 2
Engine oil maintenance
data• After changing engine oilP. 4 2 5
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. 4 3 7
After reconnecting or performing main tenance on the 12 volt battery, the
hybrid system may not start. ( P. 431) Also, the following items must be
initialized for normal system operation.

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