Page 560 of 660
5607-2. Steps to take in an emergency
RX450h_U_OM0E013U
NOTICE
■Be careful when driving over bumps with the compact spare tire installed on the vehi-
cle
When driving with the compact spare tire installed, the vehicle height will be different
than when driving with standard tires. Be careful when driving over uneven road sur-
faces, etc.
■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 trans-
mitter, contact your Lexus dealer as the tire pressure warning valve and transmitter
may be damaged if not handled correctly.
Page 578 of 660
5787-2. Steps to take in an emergency
RX450h_U_OM0E013U
Stop the hybrid system. Shift the shift lever to P and set the parking brake.
Remove the mud, snow or sand from around the front wheels.
Place wood, stones or some other materi al under the front wheels to help pro-
vide traction.
Restart the hybrid system.
Shift the shift lever to D or R and rele ase the parking brake. Then, while exer-
cising caution, depress the accelerator pedal.
■When it is difficult to free the vehicle
If the vehicle becomes stuck
Carry out the following procedures if the tires spin or the vehicle becomes
stuck in mud, dirt or snow:
Press to turn off TRAC.
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Page 589 of 660

5898-1. Specifications
8
Vehicle specifications
RX450h_U_OM0E013U
Type A
Type B
Steering
Free playLess than 1.2 in. (30 mm)
Tires and wheels
Tire size235/65R18 106V, T165/90D18 107M (spare)
Tire inflation pressure
(Recommended cold tire
inflation pressure)
Front tire33 psi (230 kPa, 2.3 kgf/cm2 or bar)
Rear tire
33 psi (230 kPa, 2.3 kgf/cm2 or bar)Spare tire
60 psi (420 kPa, 4.2 kgf/cm2 or bar)
Driving at high speeds (above 100 mph [160 km/h])
(in countries where such speeds are permitted by
law)
Add 5 psi (30 kPa, 0.3 kgf/cm2 or bar) to the
front and rear tires. Never exceed the maximum
cold tire inflation pressu re indicated on the tire
sidewall.
Wheel size18 8 J, 18 4 T (spare)
Wheel nut torque76 ft•lbf (103 N•m, 10.5 kgf•m)
Tire size235/55R20 102V, T165/90D18 107M (spare)
Tire inflation pressure
(Recommended cold tire
inflation pressure)
Front tire
33 psi (230 kPa, 2.3 kgf/cm2 or bar)
Rear tire33 psi (230 kPa, 2.3 kgf/cm2 or bar)
Spare tire
60 psi (420 kPa, 4.2 kgf/cm2 or bar)Driving at high speeds (above 100 mph [160 km/h])
(in countries where such speeds are permitted by
law)
Add 11 psi (70 kPa, 0.7 kgf/cm2 or bar) to the
front and rear tires. Never exceed the maximum
cold tire inflation pressu re indicated on the tire
sidewall.
Wheel size20 8 J, 18 4 T (spare)
Wheel nut torque76 ft•lbf (103 N•m, 10.5 kgf•m)
Page 595 of 660

5958-1. Specifications
8
Vehicle specifications
RX450h_U_OM0E013U
Tire size( P. 597)
DOT and Tire Identification Number (TIN) ( P. 596)
Location of treadwear indicators (P. 487)
Tire ply composition and materials
Plies are layers of rubber-c oated 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 put into the tire. A tube type tire
has a tube inside the tire and the tube maintains the air pressure.
Load limit at maximum cold tire inflation pressure ( P. 490)
Maximum cold tire inflation pressure ( P. 589)
This means the pressure to which a tire may be inflated.
Uniform tire quality grading
For details, see “Uniform Tire Quality Grading” that follows.
Summer tires or all season tires ( P. 491)
An all season tire has “M+S” on the side wall. A tire not marked “M+S” is a summer
tire.
“TEMPORARY USE ONLY”
A compact spare tire is identified by the phrase “TEMPORARY USE ONLY” molded
on its sidewall. This tire is designed for temporary emergency use only.
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Page 599 of 660

5998-1. Specifications
8
Vehicle specifications
RX450h_U_OM0E013U
This information has been prepared in accordance with regulations issued by the
National Highway Traffic Safety Administra tion of the U.S. Department of Trans-
portation.
It provides the purchasers and/or prospe ctive purchasers of Lexus vehicles with
information on uniform tire quality grading.
Your Lexus dealer will help answer any ques tions you may have as you read this infor-
mation.
■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 rati ng based on the wear rate of the tire
when tested under controlled conditio ns 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 actua l conditions of their use.
Performance may differ significantly from the norm due to variations in driving
habits, service practices and difference s 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 rep-
resent 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.
Uniform Tire Quality Grading
Page 600 of 660
6008-1. Specifications
RX450h_U_OM0E013U
■Temperature A, B, C
The temperature grades are A (the highes t), 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 ma terial of the tire to degenerate and
reduce tire life, and excessive temperature can lead to sudden tire failure.
Grade C corresponds to a level of perfor mance 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 of a tire assume that it is properly inflated and
not overloaded.
Excessive speed, underi nflation, or excessive loading, either separately or in com-
bination, can cause heat buildup and possible tire failure.
Page 619 of 660
619
RX450h_U_OM0E013U
8
Vehicle specifications
8-3. Initialization
Items to initialize
The following items must be initialized for normal system operation after such
cases as the 12-volt battery being reconnected, or maintenance being per-
formed on the vehicle.
ItemWhen to initializeReference
Message indicating mainte-
nance is required (U.S.A. only)• After the maintenance is per- formedP. 466
Tire pressure warning system
• When changing the tire inflationpressure by changing traveling
speed
• When changing the tire size
• When rotating the tires
P. 489
Oil maintenance• After the maintenance is per- formedP. 478
Power back door• After reconnecting or changingthe 12-volt batteryP. 150
Page 652 of 660

652Alphabetical index
RX450h_U_OM0E013U
Radar cruise control (dynamic radar cruise control) ........................ 323
Radar cruise control (dynamic radar cruise control
with full-speed range) ........................ 311
Radiator ....................................................480
Rear Cross Traffic Alert .................... 363
Rear door sunshades .......................... 443
Rear seat Folding down the rear seatbacks ............................................. 165
Rear seat heaters....................................416
Rear side marker lights Light switch ............................................ 251
Replacing light bulbs ......................... 513
Rear turn signal lights Replacing light bulbs ......................... 513
Turn signal lever ................................. 244
Wattage ................................................. 590
Rear view mirror Inside rear view mirror ..................... 183
Outside rear view mirrors .............. 185
Rear window defogger ...................... 409
Rear window wiper.............................. 265 Refueling................................................... 267
Capacity.................................................584
Fuel types...............................................584
Opening the fuel tank cap ............ 267
When the fuel filler door cannot be opened ......................... 269
Regenerative braking.............................78
Remote Touch
*.................................... 398
Replacing Electronic key battery .................... 506
Fuses ....................................................... 508
Light bulbs...............................................513
Tires .......................................................... 549
Windshield wiper inserts ...............504
Reporting safety defects for U.S. owners ...................................622
Resetting the message indicating maintenance is required .................466
Rev indicator ..............................................99
Rev peak ......................................................99
Road accident cautions ........................ 83
R