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

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4-3. Do-it-yourself maintenance
4
Maintenance and care
Tires
Replace or rotate tires in accordance with maintenance schedules and
tread wear.
■Checking tires
New tread
Tread wear indicator
Worn tread
The location of tread wear indi-
cators is shown by the “TWI” or
“ ”

marks, etc., molded on the
sidewall of each tire.
Check spare tire condition and
inflati
on pressure if not rotated.
■Tire rotation
Rotate the tires in the order
sho
wn.
Lexus recommends tire rotation
in accordance with the mainte -
nance schedule to equalize tire
w
ear and extend tire life.
Do not fail to initialize the tire
pr
essure warning system after
tire rotation.
■ The tire pressure warning system
Your Lexus is equipped with a tire pr
essure warning system that uses
tire pressure warning valves and transmitters to detect low tire infla -
tion pressure before serious problems arise. ( P. 4 3 3, 438 )
Front

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4-3. Do-it-yourself maintenance
Installing tire pressure warning valves and transmitters
When replacing tires or wheels, tire pressure warning valves and trans-
mitters must also be installed. Tire pr
essure warning valves and transmit-
ters can be installed in any of the following three ways:
● T
ire pressure warning valves and transmitters can be removed from the
old wheels and installed on the new wheels.
● When r
eplacing only the tire, the ti re pressure warning valve and trans-
mitter already installed on the wheel does not need to be replaced.
● R
eplacing both a wheel and its tire pressure warning valve and trans -
mitter.
When new tire pressure warning va lv
es and transmitters are installed,
new tire pressure warning valve and transmitter ID codes must be regis-
tered in the tire pressure warning ECU and tire pressure warning system
must be initializ
ed. (P. 3 7 7, 378 )

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4-3. Do-it-yourself maintenance
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Maintenance and care
Initializing the tire pressure warning system
■The tire pressure warning system must be initialized in the following
circumstances:
● When r
otating the tires on vehicles differing with front and rear tire
inflation pressures.
● When changing the tir
e inflation pressure by changing traveling
speed or load weight, etc.
● When changing the tir
e size.
When the tire pressure warning sys tem is initializ
ed, the current tire
inflation pressure is set as the pressure benchmark.
■ Ho
w to initialize the tire pressure warning system
Park the vehicle in safe place and turn the po
wer switch to “OFF”
mode.
While the vehicle is moving, initialization is not performed.
Adjust the tire inflation pressure to the specified cold tire inflation
pressure level. ( P. 4 8 7 )
Make sure to adjust the tire pressure to the specified cold tire inflation
pressure level. The tire pressure warning system will operate based on
this pressure level.
Turn the power switch to “IG-ON” mode.
STEP1
STEP2
STEP3

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4-3. Do-it-yourself maintenance
Push and hold the tire pressure
warning reset switch until the tire
pressure warning light blinks
slowly three times and the mes-
sage “PRESSURE INITIAL”
appears on the multi-information
display

.
Wait for a few minutes with the “IG-ON” mode, and then turn
power switch to “OFF” mode.
Registering and selecting ID codes
■ Registering ID codes
2 sets of tire pressure warning va lv
e and transmitter ID codes can be
registered. Once a second set of tire s (winter tires etc.) is registered at
“2nd”, you can switch b etween tire set settings si mply by pressing the
tire pressure warning select switch.
There are 2 settings:
“MAIN” position: The ID code of the tir
e pressure warning valve and
transmitter on the tires originally inst alled on the vehicle is registered.
“2nd” position: The code is not registered. When you replace a new set
of tir
es, purchase tire pressure warning valves and transmitters from
your Lexus dealer and have the new ID code registered by your Lexus
dealer.
STEP4
STEP5

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4-3. Do-it-yourself maintenance
4
Maintenance and care
■Selecting ID codes
When replacing tires, make sure to select the ID code set that matches
the ne
w tire set. If the incorrect ID code is selected, the tire pressure
warning system will not operate properly. After a certain period of
time, the tire pressure warning li ght comes on after blinking for 1
minute to indicate a system malfunction.
“MAIN”
“2nd”
■When to replace your vehicle’s tires
Tires should be replaced if:
●You have tire damage such as cuts, splits, cracks deep enough to expose the
fabric or bulges indicating internal damage
●A tire goes flat repeatedly or cannot be properly repaired due to the size or
location of a cut or other damage
If you are not sure, consult with your Lexus dealer.
■Tire life
Any tire over 6 years old must be checked by a qualified technician even if they
h
ave seldom or never been used or damage is not obvious.
■If the tread wears down below 0.16 in. (4 mm) on snow tires
The effectiveness of snow tires is lost.
■Low profile tires (245/40R18, P245/40R18 and 245/40ZR18 tires)
Generally, low profile tires will wear more rapidly and tire grip performance will be
r
educed on snowy and/or icy roads when co mpared to standard tires. Be sure to
use snow tires or snow chains on snowy and/or icy roads and drive carefully at a
speed appropriate for road and weather conditions.

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4-3. Do-it-yourself maintenance
■Maximum load of tire
Check that the maximum load of the replaced tire is greater than 1 /2 of the Gross
Axle Weight Ratings (GAWR) of either the front axle or the rear axle, whichever is
greater. 
As for the maximum load of the tire, see the load limit at maximum cold tire inflation
pressure mentioned on the sidewall of the tire, and as for the Gross Axle Weight
Ratings (GAWR), see the Certification Label. (
P. 385, 492).
■Tire types
1 Summer tires
Summer tires are high-speed performance tires best suited to highway driving
under dry conditions. Since summer tires do not have the same traction perfor-
mance as snow tires, summer tires are in adequate for driving on snow-covered
or icy roads. For driving on snow-covered roads or icy roads, the use of snow tires
is recommended. When installing snow tires, be sure to replace all four tires.
2 All season tires All season tires are designed to provide better traction in snow and to be ade-
quate for driving in most winter conditions , as well as for use year round. All sea-
son tires, however, do not have adequa te traction performance compared with
snow tires in heavy or loos e snow. Also, all season tires fall short in acceleration
and handling performance compared with summer tires in highway driving.
3Snow tires For driving on snow-covered roads or icy roads, we recommend using snow tires.
If you need snow tires, select tires of the same size, construction and load capac-
ity as the originally installed tires. Since your vehicle has radial tires as original
equipment, make sure your snow tires also have radial construction. Do not install
studded tires without first checking loca l regulations for possible restriction.
Snow tires should be installed on all wheels. ( P. 1 74 )
■Initializing the tire pressure warning system
Initialize the tires with the tire inflatio n pressure adjusted to the specified level.

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4-3. Do-it-yourself maintenance
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Maintenance and care
CAUTION
■When inspecting or replacing tires
Observe the following precautions to prevent accidents. Failure to do so may cause
damage to parts of the drive train, as well as dangerous handling characteristics,
which may lead to fatal or injury accidents.
●Do not mix tires of different makes, models, tread patterns or tread wear.
●Do not use tire sizes other than those recommended by Lexus.
●Do not mix radial, bias-belted, or bias-ply tires.
●Do not mix summer, all season and winter tires.
■When initializing the tire pressure warning system
Do not push the reset switch without first ad justing the tire inflation pressure to the
specified level. Otherwise, the tire pressure warning light may not come on even if
the tire inflation pressure is low, or it may come on when the tire inflation pressure is
actually normal.
NOTICE
■Repairing or replacing tires, wheels and tire pressure warning valves and trans-
mitters
●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.
●When replacing tires, make sure also to replace the tire pressure warning valve
and transmitter grommets.
■Do not use puncture sealant sprays to repair flats
Puncture sealant sprays may damage tire pressure tire pressure warning valves and
transmitters.

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4-3. Do-it-yourself maintenance
NOTICE
■Driving on rough roads
Take particular care when driving on roads with loose surfaces or potholes.
These conditions may cause losses in tire inflation pressure, reducing the cushion-
ing ability of the tires. In addition driving on rough roads may cause damage to the
tires themselves, as well as the vehicle’s wheels and body.
■Low profile tires (245/40R18, P245/40R18 and 245/40ZR18 tires)
Low profile tires may cause greater damage than usual to the tire wheel when
receiving impact from the road surface. Therefore pay attention to the following:
●Be sure to use proper tire inflation pressure. If tires are under-inflated, they may
be damaged more severely.
●Avoid hot holes, uneven pavement, curbs and other road hazards. Failure to do so
can lead to severe tire and wheel damage.
■If tire inflation pressures become low while driving
Do not continue driving, or your tires and/or wheels may be ruined.

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4-3. Do-it-yourself maintenance
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Maintenance and care
■Effects of incorrect tire inflation pressure
Driving with incorrect tire inflation pressure may result in the following:
●Reduced fuel efficiency
●Reduced driving comfort and tire life
●Reduced safety
●Damage to the drive train
If a tire needs frequent refilling, have it checked by your Lexus dealer.
■Instructions for checking tire inflation pressure
When checking tire inflation pressure, observe the following:
●Check 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 mile or 1.5 km, you will get an accurate cold tire inflation pressure
reading.
●Always use a tire pressure gauge. 
The appearance of the tire can be misleadi ng. In addition, 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 placed so that the vehicle is bal-
anced.

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4-3. Do-it-yourself maintenance
CAUTION
■Proper inflation is critical to save tire performance
Keep your tires properly inflated. Otherwise, the following conditions may occur
and result in an accident causing death or serious injury.
●Excessive wear
●Uneven wear
●Poor handling
●Possibility of blowouts resulting from overheated tires
●Poor sealing of the tire bead
●Wheel deformation and/or tire separation
●A greater possibility of tire damage from road hazards
NOTICE
■When inspecting and adjusting tire inflation pressure
Be sure to reinstall the tire valve caps.
Without the valve caps, dirt or moisture co uld get into the valve and cause air leak-
age, which could result in an accident. If the caps have been lost, replace them as
soon as possible.