Page 542 of 660

5427-2. Steps to take in an emergency
RX450h_U_OM0E013U
WARNING
■Maintenance of the tires
Each tire, including the spare (if provided), should be checked monthly when cold and
inflated to the inflation pressure recomm ended by the vehicle manufacturer on the
vehicle placard or tire inflation pressure 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 [tire and load in formation 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 moni-
toring system (TPMS-tire pressure warning system) that illuminates a low tire pressure
telltale (tire pressure warning light) when on e or more of your tires is significantly
under-inflated. Accordingly, when the low ti re pressure telltale (tire pressure warning
light) illuminates, you should st op and check your tires as soon as possible, and inflate
them to the proper pressure. Driving on a significantly under-inflat ed 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 wa rning 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 reached the le vel to trigger illumination of the TPMS low
tire pressure telltale (tir e pressure warning light).
Your vehicle has also been equipped with a TPMS (tire pressure warning system) mal-
function indicator to indicate when the system is not operating properly. The TPMS
(tire pressure warning system) malfunction indi cator is combined with the low tire pres-
sure telltale (tire pressure warning light). When the system detects a malfunction, the
telltale will flash for approximately one mi nute and then remain continuously illumi-
nated. This sequence will cont inue upon subsequent vehicle start-ups as long as the
malfunction exists. When the malfunction indicator is illuminated, the system may not
be able to detect or signal low tire pressure as intended.
TPMS (tire pressure warning system) malfunctions may occur for a variety of reasons,
including the installation of replacement or alternate tires or wheels on the vehicle that
prevent the TPMS (tire pressure warning system) from functioning properly. Always
check the TPMS (tire pressure warning system) malfunction telltale after replacing one
or more tires or wheels on your vehicle to ensure that the replacement or alternate
tires and wheels allow the TPMS (tire pressure warning system) to continue to function
properly.
NOTICE
■To ensure the tire pressure warning system operates properly
Do not install tires with different specifications or makers, as the tire pressure warning
system may not operate properly.
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 594 of 660
5948-1. Specifications
RX450h_U_OM0E013U
Full-size tire
Compact spare tire
Tire information
Typical tire symbols
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.
1
2
3
4
5
6
7
8
9
10
11
Page 596 of 660
5968-1. Specifications
RX450h_U_OM0E013U
DOT symbol*
Tire Identification Number (TIN)
Tire manufacturer’s identification
mark
Tire size code
Manufacturer’s optional tire type
code (3 or 4 letters)
Manufacturing week
Manufacturing year
*: The DOT symbol certifies that the tire co nforms to applicable Federal Motor Vehicle
Safety Standards.
Typical DOT and Tire Identification Number (TIN)
1
2
3
4
5
6
7
Page 597 of 660
5978-1. Specifications
8
Vehicle specifications
RX450h_U_OM0E013U
■Typical tire size information
The illustration indicates typical tire size.Tire use
(P = Passenger car,
T = Temporary use)
Section width (millimeters)
Aspect ratio
(tire height to section width)
Tire construction code
(R = Radial, D = Diagonal)
Wheel diameter (inches)
Load index (2 digits or 3 digits)
Speed symbol (alphabet with one letter)
■Tire dimensionsSection width
Tire height
Wheel diameter
Tire size
1
2
3
4
5
6
7
1
2
3
Page 602 of 660

6028-1. Specifications
RX450h_U_OM0E013U
Production options weight
The combined weight of in stalled regular production
options weighing over 5 lb. (2.3 kg) in excess of the
standard items which they re place, not previously con-
sidered in curb weight or accessory weight, including
heavy duty brakes, ride levelers, roof rack, heavy duty
12-volt battery, and special trim
RimA metal support for a tire or a tire and tube assembly
upon which the tire beads are seated
Rim diameter
(Wheel diameter)Nominal diameter of the bead seat
Rim size designationRim diameter and width
Rim type designationThe industry manufacturer’s designation for a rim by
style or code
Rim widthNominal distance between rim flanges
Vehicle capacity weight
(Total load capacity)The rated cargo and luggage load plus 150 lb. (68 kg)
times the vehicle’s desi gnated seating capacity
Vehicle maximum load on
the tireThe load on an individual tire that is determined by dis-
tributing to each axle its share of the maximum loaded
vehicle weight, and dividing by two
Vehicle normal load on the
tire
The load on an individual tire that is determined by dis-
tributing to each axle its sh are of curb weight, accessory
weight, and normal occupant weight (distributed in
accordance with Table 1
* below), and dividing by two
Weather sideThe surface area of the rim not covered by the inflated
tire
BeadThe part of the tire that is made of steel wires, wrapped
or reinforced by ply cords an d that is shaped to fit the
rim
Tire related termMeaning
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