2021 LEXUS NX300h width

4378-1. Specifications
LEXUS NX300h Owners Manual_USA_M78578_en
8
Vehicle specifications
Chafer
This information has been prepared in
accordance with regulations issued by
the National Highway Traffic Safety
Administration of the U.S. Department
of Transportation.
It provides the purchasers and/or pro-
spective purchasers of Lexus vehicles
with information on uniform tire quality
grading.
Your Lexus dealer will help answer any
questions you may have as you read this
information.
■DOT quality grades
All passenger vehicle tires must con-
form 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
rating based on the wear rate of the tire
when tested under controlled condi-
tions 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 performa nce of tires depends
upon the actual conditions of their use,
however, and may depart significantly from
the norm due to variatio ns in driving habits,
service practices and differences 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
represent the tire’s ability to stop on
wet pavement as measured under con-
trolled conditions on specified govern-
ment 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.
■Temperature A, B, C
The temperature grades are A (the
highest), B, and C, representing the
tire’s resistance to the generation of
heat and its ability to dissipate heat
when tested under controlled condi-
tions on a specified indoor laboratory
test wheel.
Sustained high temperature can cause the
material of the tire to degenerate and
reduce tire life, and excessive temperature
can lead to sudd en tire failure.
Grade C corresponds to a level of perfor-
mance which all passenger car tires must
meet under the Fede ral 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 for this
tire are established for a tire that is prop-
erly inflated and not overloaded.
Excessive speed, unde rinflation, or exces-
sive loading, either separately or in combi-
Uniform Tire Quality Grading
K

4388-1. Specifications
LEXUS NX300h Owners Manual_USA_M78578_en
nation, can cause heat buildup and
possible tire failure.
Glossary of tire terminology
Tire related
termMeaning
Cold tire
inflation
pressure
Tire pressure when the vehi-
cle has been parked for
three hours or more, or has
not been driven more than 1
mile or 1.5 km under that
condition
Maximum
inflation
pressureThe maximum cold inflated
pressure to which a tire may
be inflated, shown on the
sidewall of the tire
Recom-
mended
inflation
pressureCold tire inflation pressure
recommended by a manu-
facturer
Accessory
weight
The combined weight (in
excess of those standard
items which may be
replaced) of transmission,
power steering, power
brakes, power windows,
power seats, radio and
heater, to the extent that
these items are available as
factory-installed equipment
(whether installed or not)
Curb weight
The weight of a motor vehi-
cle with standard equip-
ment, including the
maximum capacity of fuel,
oil and coolant, and if so
equipped, air conditioning
and additional weight
optional engine
Maximum
loaded vehi-
cle weight
The sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity weight
(d) Production options
weight
Normal
occupant
weight150 lb. (68 kg) times the
number of occupants speci-
fied in the second column of
Table 1
* that follows
Occupant
distribution
Distribution of occupants in
a vehicle as specified in the
third column of Table 1
*
below
Production
options
weight
The combined weight of
installed regular production
options weighing over 5 lb.
(2.3 kg) in excess of the
standard items which they
replace, not previously con-
sidered in curb weight or
accessory weight, including
heavy duty brakes, ride lev-
elers, roof rack, heavy duty
12-volt battery, and special
trim
Rim
A metal support for a tire or
a tire and tube assembly
upon which the tire beads
are seated
Rim diame-
ter
(Wheel
diameter)
Nominal diameter of the
bead seat
Rim size des-
ignationRim diameter and width
Tire related termMeaning

4398-1. Specifications
LEXUS NX300h Owners Manual_USA_M78578_en
8
Vehicle specifications
Rim type
designationThe industry manufac-
turer’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 lug-
gage load plus 150 lb. (68
kg) times the vehicle’s des-
ignated seating capacity
Vehicle max-
imum load
on the tire
The load on an individual
tire that is determined by
distributing to each axle its
share of the maximum
loaded vehicle weight, and
dividing by two
Vehicle nor-
mal load on
the tire
The load on an individual
tire that is determined by
distributing to each axle its
share of curb weight, acces-
sory weight, and normal
occupant weight (distrib-
uted in accordance with
Table 1
* below), and dividing
by two
Weather
sideThe surface area of the rim
not covered by the inflated
tire
Bead
The part of the tire that is
made of steel wires,
wrapped or reinforced by
ply cords and that is shaped
to fit the rim
Bead sepa-
rationA breakdown of the bond
between components in the
bead
Tire related termMeaning
Bias ply tire
A pneumatic tire in which
the ply cords that extend to
the beads are laid at alter-
nate angles substantially
less than 90 degrees to the
centerline of the tread
Carcass
The tire structure, except
tread and sidewall rubber
which, when inflated, bears
the load
Chunking
The breaking away of
pieces of the tread or side-
wall
CordThe strands forming the
plies in the tire
Cord sepa-
rationThe parting of cords from
adjacent rubber com-
pounds
Cracking
Any parting within the
tread, sidewall, or innerliner
of the tire extending to cord
material
CT
A pneumatic tire with an
inverted flange tire and rim
system in which the rim is
designed with rim flanges
pointed radially inward and
the tire is designed to fit on
the underside of the rim in a
manner that encloses the
rim flanges inside the air
cavity of the tire
Extra load
tire
A tire designed to operate
at higher loads and at
higher inflation pressures
than the corresponding
standard tire
Tire related termMeaning

4408-1. Specifications
LEXUS NX300h Owners Manual_USA_M78578_en
GrooveThe space between two
adjacent tread ribs
Innerliner
The layer(s) forming the
inside surface of a tubeless
tire that contains the inflat-
ing medium within the tire
Innerliner
separationThe parting of the innerliner
from cord material in the
carcass
Intended
outboard
sidewall
(a) The sidewall that con-
tains a whitewall, bears
white lettering, or bears
manufacturer, brand, and/or
model name molding that is
higher or deeper than the
same molding on the other
sidewall of the tire, or
(b) The outward facing side-
wall of an asymmetrical tire
that has a particular side
that must always face out-
ward when mounted on a
vehicle
Light truck
(LT) tire
A tire designated by its
manufacturer as primarily
intended for use on light-
weight trucks or multipur-
pose passenger vehicles
Load rating
The maximum load that a
tire is rated to carry for a
given inflation pressure
Maximum
load rating
The load rating for a tire at
the maximum permissible
inflation pressure for that
tire
Tire related
termMeaning
Maximum
permissible
inflation
pressureThe maximum cold inflation
pressure to which a tire may
be inflated
Measuring
rimThe rim on which a tire is fit-
ted for physical dimension
requirements
Open splice
Any parting at any junction
of tread, sidewall, or inner-
liner that extends to cord
material
Outer diam-
eterThe overall diameter of an
inflated new tire
Overall
width
The linear distance between
the exteriors of the sidewalls
of an inflated tire, including
elevations due to labeling,
decorations, or protective
bands or ribs
Passenger
car tire
A tire intended for use on
passenger cars, multipur-
pose passenger vehicles,
and trucks, that have a gross
vehicle weight rating
(GVWR) of 10,000 lb. or
less.
PlyA layer of rubber-coated
parallel cords
Ply separa-
tionA parting of rubber com-
pound between adjacent
plies
Tire related termMeaning

4418-1. Specifications
LEXUS NX300h Owners Manual_USA_M78578_en
8
Vehicle specifications
*:Table 1  Occupant loading and distri-
bution for vehicle normal load for vari-
ous designated seating capacities
Pneumatic
tire
A mechanical device made
of rubber, chemicals, fabric
and steel or other materials,
that, when mounted on an
automotive wheel, provides
the traction and contains
the gas or fluid that sustains
the load
Radial ply
tire
A pneumatic tire in which
the ply cords that extend to
the beads are laid at sub-
stantially 90 degrees to the
centerline of the tread
Reinforced
tire
A tire designed to operate
at higher loads and at
higher inflation pressures
than the corresponding
standard tire
Section
width
The linear distance between
the exteriors of the sidewalls
of an inflated tire, excluding
elevations due to labeling,
decoration, or protective
bands
SidewallThat portion of a tire
between the tread and bead
Sidewall sep-
arationThe parting of the rubber
compound from the cord
material in the sidewall
Tire related termMeaning
Snow tire
A tire that attains a traction
index equal to or greater
than 110, compared to the
ASTM E-1136 Standard
Reference Test Tire, when
using the snow traction test
as described in ASTM F-
1805-00, Standard Test
Method for Single Wheel
Driving Traction in a
Straight Line on Snow-and
Ice-Covered Surfaces, and
which is marked with an
Alpine Symbol ( ) on at
least one sidewall
Test rim
The rim on which a tire is fit-
ted for testing, and may be
any rim listed as appropri-
ate for use with that tire
Tread
That portion of a tire that
comes into contact with the
road
Tread ribA tread section running cir-
cumferentially around a tire
Tread sepa-
rationPulling away of the tread
from the tire carcass
Treadwear
indicators
(TWI)
The projections within the
principal grooves designed
to give a visual indication of
the degrees of wear of the
tread
Wheel-hold-
ing fixtureThe fixture used to hold the
wheel and tire assembly
securely during testing
Tire related termMeaning