Lexus GS430 2006 Scheduled Maintenance Guide / LEXUS 2006 GS430/GS300 FROM JAN. 2005 PROD. OWNER'S MANUAL (OM30649U)

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540
The recommended cold tire inflation pressure, tire
size and the combined weight of occupants and
cargo (vehicle capacity weight) are described on the
tire and loading information label.
You should check the tire inflation pressure every two
weeks, or at least once a month. And do not forget the
spare! The inflation pressure for the spare tire should be
420 kPa (4.3 kgf/cm
2, 4.2 bar, 60 psi).
The following instructions for checking tire inflation
pressure should be observed:
 The pressure should be checked only when the
tires are cold. If your vehicle has been parked for at
least 3 hours and has not been driven for more than
1.5 km or 1 mile since, you will get an accurate cold
tire inflation pressure reading.
 Always use a tire pressure gauge. The appearance
of the tire can be misleading. Besides, tire inflation
pressures that are even just a few pounds off can
degrade ride and handling.
 Do not bleed or reduce tire inflation pressure after
driving. It is normal for the tire inflation pressure to
be higher after driving.
 Never exceed the vehicle capacity weight.
Passengers and luggage weight should be located so
that the vehicle is balanced. Inspection and adjustment procedureG63001
 1Tire valve
2Tire pressure gauge
1. Remove the tire valve cap.
2. Press the tip of the tire pressure gauge to the tire
valve.
3. Read the pressure using the graduations of the
gauge.
4. In case the tire inflation pressure is not within the
prescribed range, insert the compressed air from the
valve. In case of applying too much air, press the center
of the valve and release the air to adjust.
5. After completing the tire inflation pressure
measurement and adjustment, apply soapy water to the
valve and check for leakage.

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6. Install the tire valve cap.
If a gauge and air pump are not available, have your
vehicle checked by your Lexus dealer.
CAUTION
Be sure to reinstall the tire valve caps. Without the
valve caps, dirt or moisture could get into the
valve core and cause air leakage. If the caps have
been lost, have new ones put on as soon as
possible.
Incorrect tire inflation pressure may waste fuel, reduce
the comfort of driving, reduce tire life and make your
vehicle less safe to drive.
If a tire needs frequent refilling, have it checked by your
Lexus dealer.
CAUTION
Keep your tires properly inflated. Otherwise, the
following conditions may occur and cause an
accident resulting in death or serious injuries.
Low tire pressure (underinflation):
 Excessive wear
 Uneven wear
 Poor handling
 Possibility of bl owouts from an overheated tire
 Poor sealing of the tire bead
 Wheel deformation and/or tire separation
 A greater possibility of tire damage from road
hazards
High tire pressure (overinflation):
 Poor handling
 Excessive wear
 Uneven wear
 A greater possibility of tire damage from road
hazards

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542
TIRE INFORMATION
Tire symbols (Standard and runflat tire)
G63006
The illustration indicates typical tire symbols.

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543
1 Tire size: For details, see “Tire size” on page
546.
2 DOT and Tire Identification Number (TIN): For
details, see “DOT and Tire Identification Number
(TIN)” on page 546.
3 Tire ply composition and materials : Plies
mean a layer of rubber −coated parallel cords.
Cords mean the strands forming the plies in the
tire.
4 Load limit at maximum cold tire inflation
pressure: For details, see “Checking and
replacing tires” on page 554.
5 Uniform tire quality grading For details, see
“Uniform tire quality grading” on page 548.
6 Maximum cold tire inflation pressure: This
means the pressure to which a tire may be
inflated. For recommended cold tire inflation
pressure, see “Specifications” on page 537.
7 “TUBELESS” or “TUBE TYPE”: A tubeless tire
does not have a tube inside the tire and air is
directly filled in the tire. A tube type tire has a
tube inside the tire and the tube maintains the air
pressure.
8 Radial tires or biasply tires : A radial tire has
“RADIAL” on the sidewall. A tire not marked with
“RADIAL” is a bias −ply tire.
9 Runflat tire (RFT) or standard tire: This
vehicle can be equipped with either run −flat tires
(RFT) or standard tires. A “RFT” or “DSST” mark
is molded on the sidewall of the run −flat tire. For
details, see “Run −flat tires” on page 552.
10 Location of tread wear indicators: For details,
see “Checking and replacing tires” on page 554.
11 Summer tire or all season tire: An all season
tire has “M+S” on the sidewall. The tire not
marked with “M+S” is a summer tire. For details,
see “Types of tires” on page 553.

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544
Tire symbols (Compact spare tire)
G63007
The illustration indicates typical tire symbols.

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545
1 “TEMPORARY USE ONLY”: A compact spare
tire is identified by the phrase “TEMPOTRARY
USE ONLY” molded into its sidewall. This tire is
designed for temporary emergency use only. For
details, see “Compact spare tire” on page 471.
2 Tire size: For details, see “Tire size” on page
546.
3 DOT and Tire Identification Number (TIN): For
details, see “DOT and Tire Identification Number
(TIN)” on page 546.
4 Load limit at maximum cold tire inflation
pressure: For details, see “Checking and
replacing tires” on page 554.
5 Maximum cold tire inflation pressure: This
means the pressure to which a tire may be
inflated. For recommended cold tire inflation
pressure, see “Specifications” on page 532.
6 Tire ply composition and materials : Plies
mean a layer of rubber −coated parallel cords.
Cords mean the strands forming the plies in the
tire.
7 Location of tread wear indicators: For details,
see “Checking and replacing tires” on page 554.
8 “TUBELESS” or “TUBE TYPE”: A tubeless tire
does not have a tube inside the tire and air is
directly filled in the tire. A tube type tire has a
tube inside the tire and the tube maintains the air
pressure.
9 Radial tires or biasply tires : A radial tire has
“RADIAL” on the sidewall. A tire not marked with
“RADIAL” is a bias −ply tire.

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546
DOT and Tire Identification Number (TIN)
63SA11a
The illustration indicates typical DOT and Tire
Identification Number (TIN)
1“DOT” symbol
2Tire Identification Number (TIN)
3Tire manufacturer’s identification mark
4Tire size code
5Manufacturer’s optional tire type code
(3 or 4 letters)
6Manufacturing week
7Manufacturing year
The “DOT” symbol certifies that the tire conforms to
applicable Federal Motor Vehicle Safety Standards.
Tire size
63ca01
The illustrations indicate typical tire sizes.
1Tire use (P=Passenger car, T=Temporary use)
2Section width (in millimeters)
3Aspect ratio (tire height to section width)
4Speed category (alphabet with one letter)
5Tire construction code
(R=Radial, D=Diagonal)
6Wheel diameter (in inches)
7Load index (2 digits or 3 digits)
8Speed symbol (alphabet with one letter)

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G63005
 1Section width
2Tire height
3Wheel diameter
Name of each section of tire
63sa14
 1Bead
2Sidewall
3Shoulder
4Tread
5Belt
6Inner liner
7Reinforcing rubber
8Carcass
9Rim lines
10Bead wires
11Chafer

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548
Uniform tire quality grading
This information has been prepared in accordance
with regulations issued by the National Highway
Traffic Safety Administration of the U.S. Department
of Transportation. It provides the purchasers and/or
prospective purchasers of Lexus vehicles with
information on uniform tire quality grading.
Your Lexus dealer will help answer any questions
you may have as you read this information.
DOT quality grades All passenger vehicle tires
must conform to Federal Safety Requirements in
addition to these grades. Quality grades can be
found where applicable on the tire sidewall between
tread shoulder and maximum section width. For
example: Treadwear 200 Traction AA Temperature
A
Treadwear − The treadwear grade is a comparative
rating based on the wear rate of the tire when tested
under controlled conditions on a specified government
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 depends upon the actual conditions of their use,
however, and may depart significantly from the norm
due to variations in driving habits, service practices and
differences in road characteristics and climate. Traction
AA, A, B, C − The traction grades, from highest
to lowest, are AA, A, B and C, and they represent the
tire’s ability to stop on wet pavement as measured under
controlled conditions 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 tire is
based on braking (straight ahead) traction tests and
does not include cornering (turning) traction.
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 failure. The grade
C corresponds to a level of performance which all
passenger car tires must meet under the Federal Motor
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
excessive loading, either separately or in combination,
can cause heat buildup and possible tire failure.

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Glossary of tire terminology
Tire related termMeaning
Cold tire inflation
pressuretire pressure when the vehicle has been parked for at least 3 hours or m\
ore, or it
has not been driven more than 1.5 km or 1 mile under that condition
Maximum inflation
pressurethe maximum cold inflation pressure to which a tire may be inflated and \
it is shown
on the sidewall of the tire
Recommended inflation
pressurecold tire inflation pressure recommended by a manufacturer
Accessory weight
the combined weight (in excess of those standard items which may be rep\
laced) of
automatic transmission, power steering, power brakes, power windows, pow\
er
seats, radio, and heater, to the extent that these items are available as
factory−installed equipment (whether installed or not)
Curb weight
the weight of a motor vehicle with standard equipment including the maxi\
mum
capacity of fuel, oil, and coolant, and, if so equipped, air conditionin\
g and
additional weight optional engine
Maximum loaded vehicle
weight
the sum of —
(a) curb weight;
(b) accessory weight;
(c) vehicle capacity weight; and
(d) production options weight