2012 Lexus GS350 tires

675 6-3. Do-it-yourself maintenance
6
Maintenance and care
GS350/250_EE (OM30C36E)
Initializing the tire pressure warning system
The tire pressure warning system must be initialized in the fol-
lowing circumstances:
When rotating the tires.
When the tire inflation pressure is changed such as when
changing traveling speed.
When the tire pressure warning system is initialized, the current
tire inflation pressure is set as the benchmark pressure.
How to initialize the tire pressure warning system
Park the vehicle in a safe place and turn the engine switch off.
Initialization cannot be performed while the vehicle is moving.
Adjust the tire inflation pressure to the specified cold tire infla-
tion pressure level. (P. 850)
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 engine switch to IGNITION ON mode.
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677 6-3. Do-it-yourself maintenance
6
Maintenance and care
GS350/250_EE (OM30C36E)
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, and 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 any authorized Lexus dealer or repairer, or
another duly qualified and equipped professional.
Replacing tires and wheels (vehicles with the tire pressure warning system)
If the ID code of the tire pressure warning valve and transmitter is not regis-
tered, the tire pressure warning system will not work properly. After driving
for about 10 minutes, the tire pressure warning light blinks for 1 minute and
stays on to indicate a system malfunction.
Tire life
Any tire over 6 years old must be checked by a qualified technician even if it
has seldom or never been used or damage is not obvious.
Routine tire inflation pressure checks
The tire pressure warning system does not replace routine tire inflation pres-
sure checks. Make sure to check tire inflation pressure as part of your routine
of daily vehicle checks.
When rotating the tires (vehicles with the tire pressure warning system featur-
ing a tire inflation pressure display function)
Make sure that the engine switch is off. If the tires are rotated while the
engine switch is in IGNITION ON mode, the tire position information will
not be updated.
If this accidentally occurs, either turn the engine switch to off and then to
IGNITION ON mode, or initialize the system after checking that the tire
pressure is properly adjusted.

6786-3. Do-it-yourself maintenance
GS350/250_EE (OM30C36E)
Low profile tires (except 225/50R17 tires)
Generally, low profile tires will wear more rapidly and tire grip performance
will be reduced on snowy and/or icy roads when compared to standard tires.
Be sure to use snow tires or tire chains
* on snowy and/or icy roads and drive
carefully at a speed appropriate for road and weather conditions.
*: Tire chains cannot be mounted on the 19-inch tires. Snow tires should be
used instead.
If the tread on snow tires wears down below 4 mm (0.16 in.)
The effectiveness of the tires as snow tires is lost.
Situations in which the tire pressure warning system may not operate properly
(vehicles with the tire pressure warning system)
In the following cases, the tire pressure warning system may not operate
properly.
• If non-genuine Lexus wheels are used.
• A tire has been replaced with a tire that is not an OE (Original Equip-
ment) tire.
• A tire has been replaced with a tire that is not of the specified size.
• Tire chains etc. are equipped.
• Lock nuts are equipped.
• An auxiliary-supported run-flat tire is equipped.
• If a window tint that affects the radio wave signals is installed.
• If there is a lot of snow or ice on the vehicle, particularly around the
wheels or wheel housings.
• If the tire inflation pressure is extremely higher than the specified level.
• If the spare tire is in a location subject to poor radio wave signal recep-
tion.
*
• If a large metallic object which can interfere with signal reception is put
in the trunk.
*
*
: Vehicles with a full-size spare tire only
Performance may be affected in the following situations.
• Near a TV tower, electric power plant, gas station, radio station, large
display, airport or other facility that generates strong radio waves or elec-
trical noise
• When carrying a portable radio, cellular phone, cordless phone or other
wireless communication device
Vehicles with the tire inflation pressure display function: If tire position
information is not correctly displayed due to the radio wave conditions, the
display may be corrected by driving and changing the radio wave condi-
tions.

6806-3. Do-it-yourself maintenance
GS350/250_EE (OM30C36E)
The initialization operation (vehicles with the tire pressure warning system)
Make sure to carry out initialization after adjusting the tire inflation pres-
sure.
Also, make sure the tires are cold before carrying out initialization or tire
inflation pressure adjustment.
If you have accidentally turned the engine switch off during initialization, it
is not necessary to press the reset switch again as initialization will restart
automatically when the engine switch has been turned to IGNITION ON
mode for the next time.
If you accidentally press the reset switch when initialization is not neces-
sary, adjust the tire inflation pressure to the specified level when the tires
are cold, and conduct initialization again.
Warning performance of the tire pressure warning system (if equipped)
The warning of the tire pressure warning system will change in accordance
with the conditions under which it was initialized. For this reason, the system
may give a warning even if the tire pressure does not reach a low enough
level, or if the pressure is higher than the pressure that was adjusted to when
the system was initialized.
When initialization of the tire pressure warning system has failed (vehicles
with the tire pressure warning system)
Initialization can be completed in a few minutes. However, in the following
cases, the settings have not been recorded and the system will not operate
properly. If repeated attempts to record tire inflation pressure settings are
unsuccessful, have the vehicle inspected by any authorized Lexus dealer or
repairer, or another duly qualified and equipped professional.
When operating the tire pressure warning reset switch, the tire pressure
warning light does not blink 3 times.
After carrying out the initialization procedure, the tire pressure warning
light blinks for 1 minute then stays on after driving for 10 minutes.

687 6-3. Do-it-yourself maintenance
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Maintenance and care
GS350/250_EE (OM30C36E)
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 dan-
gerous handling characteristics, which may lead to an accident resulting in
death or serious injury.
Do not mix tires of different makes, models or tread patterns.
Also, do not mix tires of remarkably different treadwear.
Do not use tire sizes other than those recommended by Lexus.
Do not mix differently constructed tires (radial, bias-belted or bias-ply
tires).
Do not mix summer, all season and snow tires.
Do not use tires that have been used on another vehicle.
Do not use tires if you do not know how they were used previously.
Vehicles with a compact spare tire: Do not tow if your vehicle has a com-
pact spare tire installed.
Vehicles with an emergency tire puncture repair kit (if equipped): Do not
tow anything if a tire that has been repaired using the emergency tire
puncture repair kit is installed. The load on the tire may cause unexpected
damage to the tire.
When initializing the tire pressure warning system (vehicles with the tire
pressure warning system)
Do not operate the tire pressure warning reset switch without first adjusting
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.

689
6 6-3. Do-it-yourself maintenance
Maintenance and care
GS350/250_EE (OM30C36E)
NOTICE
Repairing or replacing tires, wheels, tire pressure warning valves, transmit-
ters and tire valve caps (vehicles with the tire pressure warning system)
When removing or fitting the wheels, tires or the tire pressure warning
valves and transmitters, contact any authorized Lexus dealer or repairer,
or another duly qualified and equipped professional as the tire pressure
warning valves and transmitters may be damaged if not handled correctly.
Make sure to install the tire valve caps. If the tire valve caps are not
installed, water could enter the tire pressure warning valves and the tire
pressure warning valves could be bound.
When replacing tire valve caps, do not use tire valve caps other than those
specified. The cap may become stuck.
To avoid damage to the tire pressure warning valves and transmitters (vehi-
cles with the tire pressure warning system)
When a tire is repaired with liquid sealants, the tire pressure warning valve
and transmitter may not operate properly. If a liquid sealant is used, contact
any authorized Lexus dealer or repairer, or another duly qualified and
equipped professional or other qualified service shop as soon as possible.
Make sure to replace the tire pressure warning valve and transmitter when
replacing the tire. (P. 674)

6906-3. Do-it-yourself maintenance
GS350/250_EE (OM30C36E)
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
cushioning 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 (except 225/50R17 tires)
Low profile tires may cause greater damage than usual to the tire wheel
when sustaining 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 potholes, uneven pavement, curbs and other road hazards. Failure
to do so may lead to severe tire and wheel damage.
If tire inflation pressure of each tire becomes low while driving
Do not continue driving, or your tires and/or wheels may be ruined.

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6 6-3. Do-it-yourself maintenance
Maintenance and care
GS350/250_EE (OM30C36E)
Tire inflation pressure
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 inflating, have it checked by any authorized Lexus
dealer or repairer, or another duly qualified and equipped professional.
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 or has not been driven
for more than 1.5 km or 1 mile, you will get an accurate cold tire inflation
pressure reading.
Always use a tire pressure gauge.
The appearance of the tire can be misleading. In addition, tire inflation pres-
sure that is even just a few pounds off can affect ride quality and handling.
Do not reduce tire inflation pressure after driving. It is normal for tire infla-
tion 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.
Make sure to maintain proper tire inflation pressure. Tire inflation
pressure should be checked at least once per month. However,
Lexus recommends that tire inflation pressure be checked once
every two weeks. (P. 850)