Page 657 of 860

GS450h_U (OM30D01U)
6576-3. Do-it-yourself maintenance
6
Maintenance and care
■If the tread on snow tires wears down below 0.16 in. (4 mm)
The effectiveness of the tires as snow tires is lost.
■Situations in which the tire pressure warning system may not operate properly
●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 Equipment) 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.
●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 electrical noise
• When carrying a portable radio, cellular phone, cordless phone or other wire- less communication device
Vehicles with the tire inflation pressure display function: If tire position information
is not correctly disp layed due to the radio wave conditions, the display may be
corrected by driving and changing the radio wave conditions.
●When the vehicle is parked, the time taken for the warning to start or go off could
be extended.
●When tire inflation pressure declines rapi dly for example when a tire has burst, the
warning may not function.
■The initialization operation
●Make sure to carry out initialization after adjusting the tire inflation pressure.
Also, make sure the tires are cold before carrying out initialization or tire inflation
pressure adjustment.
●If you have accidentally turned the power switch off during initialization, it is not
necessary to press the reset switch again as initialization will restart automatically
when the power switch has been turn ed to ON mode for the next time.
●If you accidentally press the reset switch when initialization is not necessary, adjust
the tire inflation pressure to the specified level when the tires are cold, and conduct
initialization again.
Page 659 of 860

GS450h_U (OM30D01U)
6596-3. Do-it-yourself maintenance
6
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 an accident resulting in death or seri-
ous 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 (r adial, 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.
■When initializing the tire pressure warning system
Do not operate the tire pressure warning re set 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.
■Caution regarding interference with elec tronic devices (vehicles with the tire
inflation pressure display function)
●Users of any electrical medical device other than implanted pacemakers and
implanted cardiac defibrillators should consult the manufacturer of the device for
information about its operation under the influence of radio waves.
Radio waves could have unexpected effects on the operation of such medical
devices.
●People with implanted pacemakers or car-
diac defibrillators should not come within
17.7 in. (450 mm) of the tire pressure warn-
ing system initiators. The radio waves may
affect the operation of such devices.
Page 661 of 860
661
GS450h_U (OM30D01U)6-3. Do-it-yourself maintenance
6
Maintenance and care
Tire inflation pressure
The recommended cold tire infla-
tion pressure and tire size are dis-
played on the tire and loading
information label. ( P. 790)
Tire inflation pressure
Page 664 of 860

664
GS450h_U (OM30D01U)
6-3. Do-it-yourself maintenance
Wheels
When replacing wheels, care should be taken to ensure that they are
equivalent to those removed in load capacity, diameter, rim width and
inset
*.
Replacement wheels are available at your Lexus dealer.
*: Conventionally referred to as “offset”.
Lexus does not recommend using the following:
●Wheels of different sizes or types
●Used wheels
●Bent wheels that have been straightened
●Use only Lexus wheel nuts and wren ches designed for use with your
aluminum wheels.
●When rotating, repairing or changing your tires, check that the wheel
nuts are still tight after driving 1000 miles (1600 km).
●Be careful not to damage the alum inum wheels when using tire chains.
●Use only Lexus genuine balance wei ghts or equivalent and a plastic or
rubber hammer when balancing your wheels.
If a wheel is bent, cracked or heav ily corroded, it should be replaced.
Otherwise, the tire may separate from the wheel or cause a loss of han-
dling control.
Wheel selection
Aluminum wheel precautions
Page 665 of 860

GS450h_U (OM30D01U)
6656-3. Do-it-yourself maintenance
6
Maintenance and care
■When replacing wheels
The wheels of your vehicle are equipped with tire pressure warning valves and trans-
mitters that allow the tire pressure warnin g system to provide advance warning in the
event of a loss in tire inflation pressure. Whenever wheels are replaced, tire pressure
warning valves and transmitte rs must be installed. (P. 6 5 3 )
CAUTION
■When replacing wheels
●Do not use wheels that are a different size from those recommended in the
Owner’s Manual, as this may result in a loss of handling control.
●Never use an inner tube in a leaking wheel which is designed for a tubeless tire.
Doing so may result in an accident, causing death or serious injury.
NOTICE
■Replacing tire pressure warning valves and transmitters
●Because tire repair or replacement may affect the tire pressure warning valves
and transmitters, make sure to have tires serviced by your Lexus dealer or other
qualified service shop. In addition, make sure to purchase your tire pressure
warning valves and transmitters at your Lexus dealer.
●Ensure that only genuine Lexus wh eels are used on your vehicle.
Tire pressure warning valves and transmitters may not work properly with non-
genuine wheels.
Page 719 of 860

7197-2. Steps to take in an emergency
GS450h_U (OM30D01U)
7
When trouble arises
CAUTION
■Maintenance of the tires
Each tire, including the spare (if provided), should be checked monthly when cold
and inflated to the inflation pressure re commended by the vehicle manufacturer on
the vehicle placard or tire inflation pressu re label (tire and load information label).
(If your vehicle has tires of a different size than the size indicated on the vehicle
placard or tire inflation pressure label [t ire and load information label], you should
determine the proper tire inflation pressure for those tires.)
As an added safety feature, your vehicle has been equipped with a tire pressure
monitoring system (TPMS-tire pressure wa rning system) that illuminates a low tire
pressure telltale (tire pressure warning light ) when one or more of your tires is sig-
nificantly under-inflated. Accordingly, when the low tire pressure telltale (tire pres-
sure warning light) illuminates, you should stop and check your tires as soon as
possible, and inflate them to the proper pressure. Driving on a significantly under-
inflated tire causes the tire to overheat and can lead to tire failure. Under-inflation
also reduces fuel efficiency and tire tread life, and may affect the vehicle’s handling
and stopping ability.
Please note that the TPMS (tire pressure warning system) is not a substitute for
proper tire maintenance, and it is the driver’s responsibility to maintain correct tire
pressure, even if under-inflation has not re ached the level to trigger illumination of
the TPMS low tire pressure telltale (tire pressure warning light).
Your vehicle has also been equipped with a TPMS (tire pressure warning system)
malfunction indicator to indicate when th e system is not operating properly. The
TPMS (tire pressure warning system) malfunction indicator is combined with the
low tire pressure telltale (tire pressure warning light). When the system detects a
malfunction, the telltale will flash for approximately one minute and then remain
continuously illuminated. This sequence will continue upon subsequent vehicle
start-ups as long as the malfunction exists . When the malfunction indicator is illumi-
nated, the system may not be able to detect or signal low tire pressure as intended.
Page 790 of 860
790
GS450h_U (OM30D01U)
8-1. Specifications
Ty p e A
Ty p e B
Compact spare tire
Tires and wheels
Ti r e s i z e225/50R17 94W
Tire inflation pressure
(Recommended cold tire
inflation pressure)Front tire35 psi (240 kPa, 2.4 kgf/cm2 or bar)
Rear tire 35 psi (240 kPa, 2.4 kgf/cm
2 or bar)
Wheel size17 7 1 /2J
Wheel nut torque76 f t•lbf (103 N•m, 10.5 kgf•m)
Ti r e s i z e235/45R18 94Y, P235/45R18 94V
Tire inflation pressure
(Recommended cold tire
inflation pressure)Front tire
35 psi (240 kPa, 2.4 kgf/cm2 or bar)
Rear tire 35 psi (240 kPa, 2.4 kgf/cm
2 or bar)
Wheel size18 8J
Wheel nut torque76 f t•lbf (103 N•m, 10.5 kgf•m)
Ti r e s i z eT155/70D17 110M, T145/70D18 107M
Tire inflation pressure
(Recommended cold tire
inflation pressure)
60 psi (420 kPa, 4.2 kgf/cm2 or bar)
Wheel size17 4T (T155/70D17), 18 4T (T145/70D18)
Wheel nut torque76 f t•lbf (103 N•m, 10.5 kgf•m)
Page 795 of 860
795
GS450h_U (OM30D01U)8-1. Specifications
8
Vehicle specifications
Tire information
Full-size tire
Compact spare tire
Typical tire symbols