2007 Lexus GS450h Tires

464
5-2. Steps to take in an emergency
CAUTION
■When using the spare tire
●Remember that your spare tire is specifically designed for use with your vehicle.
Do not use your spare tire on another vehicle.
●Do not use two spare tires simultaneously.
●Replace the spare tire with a standard tire as soon as possible.
●Avoid sudden acceleration, deceleration and braking, as well as sharp cornering.
■Speed limit when using the compact spare tire
Do not drive at speeds in excess of 50 mph (80 km/h) when a compact spare tire is
installed on the vehicle.
The compact spare tire is not designed for driving at high speeds. Failing to observe
this precaution may lead to an accident.

5
When trouble arises
465
5-2. Steps to take in an emergency
NOTICE
■Do not drive the vehicle with a flat tire
Do not continue driving with a flat tire.
Driving even a short distance with a flat tire can damage the tire and the wheel
beyond repair.
■Be careful when driving over bumps with the compact spare tire installed on the
vehicle
The vehicle becomes lower when driving with the compact spare tire compared to
when driving with standard tires. Be careful when driving over uneven road sur-
faces.
■Driving with tire chains and the compact spare tire
Do not fit tire chains to the compact spare tire. 
Tire chains may damage the vehicle body and adversely affect driving performance.
■When replacing the tires
●When removing or fitting the wheels, tires or the tire pressure warning valve and
transmitter, contact your Lexus dealer as the tire pressure warning valve and
transmitter may be damaged if not handled correctly.
●Replace the grommets for the tire pressure warning valves and transmitters as
well.
■To avoid damaging the tire pressure warning valves and transmitters
Do not use liquid sealants on flat tires.

478
5-2. Steps to take in an emergency
If the vehicle becomes stuck
CAUTION
■When attempting to free a stuck vehicle
If you choose to rock the vehicle back and forth to free it, make sure the surround-
ing area is clear, to avoid striking other vehicles, objects or persons. The vehicle
may also lunge forward or lunge back suddenly as it becomes free. Use extreme
caution.
■When shifting the shift lever
Be careful not to shift the shift lever with the accelerator pedal depressed. 
This may lead to unexpected rapid acceleration of the vehicle that may cause an
accident and result in death or serious injury.
NOTICE
■To avoid damaging the transm ission and other components
●Avoid spinning the wheels and racing the hybrid system.
●If the vehicle remains stuck after trying these procedures, the vehicle may require
towing to be freed.
Carry out the following procedures if the tires spin or the vehicle becomes
stuck in mud, dirt, or snow.
Stop the hybrid system. Set the parking brake and shift the shift
lever in “P”.
Remove the mud, snow, or sand fr
om around the stuck tire.
Place wood, stones or some ot her material to help pr
ovide
traction under the tires.
Restart the hybrid system.
Turn off TRAC. (  P. 1 6 4 )
Carefully apply the accelerator to free the vehicle.
STEP1
STEP2
STEP3
STEP4
STEP5
STEP6

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.

495
6-1. Specifications
6
Vehicle specifications
Tire section names
Bead
Sidewall
Shoulder
Tread
Belt
Inner liner
Reinforcing rubber
Carcass
Rim lines
Bead wires
Chafer
Uniform Tire Quality Grading
This information has been prepared in accordance with regulations
issued by the National Highway Tr affic Safety Administration of the
U.S.A. Department of Transportation.
It provides the purchasers and/or prospective purchasers of Lexus vehi -
cles with information on uniform tir
e quality grading.
Your Lexus dealer will help answer an y questions you may have as you read
this information.
■ DOT quality grades
All passenger vehicle tires must co nform to F
ederal Safety Require -
ments in addition to these grades. Quality gr
ades can be found where
applicable on the tire sidewall between tread shoulder and maximum
section width.
For example: Treadwear 200 Traction AA Temperature A

496
6-1. Specifications
■Treadwear
The treadwear grade is a comparative r
ating based on the wear rate of
the tire when tested under controll ed conditions on a specified gov-
ernment test course.
For example, a tire graded 150 would wear one and a half (1 - 1 /2) times as
well on the government course as a tire graded 100. 
The relative performance of tires de pends upon the actual conditions of
their
use, however, and may depart significantly from the norm due to varia -
tions in driving habits, service practices
and differences in road characteris-
tics and climate.
■ Traction AA, A, B, C
The traction grades, from highest to lo
west, are AA, A, B and C, and
they represent the tire's ability to stop on wet pavement as measured
under controlled condit ions on specified government test surfaces of
asphalt and concrete.
A tire marked C may have poor traction performance.
Warning: The traction grade assigned to this tir
e is based on braking
(straight ahead) traction tests and does not include cornering (turning) trac-
tion.
■ Temperature A, B, C
The temperature grades are A (the highest), B, and C, representing
the tir

e'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
tir
es 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 r
equired by law.

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.