Lexus GS350 2014 Do-it-yourself maintenance / LEXUS 2014 GS350 OWNERS MANUAL (OM30D41U)

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GS350_OM_OM30D41U_(U)8-1. Specifications
8
Vehicle specifications
Tire information
Full-size tire
Compact spare tire
Typical tire symbols

782
GS350_OM_OM30D41U_(U)
8-1. Specifications
Tire size (P. 7 8 4 )
DOT and Tire Identification Number (TIN) ( P. 783)
Location of treadwear indicators ( P. 6 4 2 )
Tire ply composition and materials
Plies are layers of rubber-coated 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. 7 8 8 )
Maximum cold tire inflation pressure ( P. 7 8 8 )
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. 6 4 7 )
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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GS350_OM_OM30D41U_(U)
7838-1. Specifications
8
Vehicle specifications
DOT symbol*
Tire Identification Number (TIN)
Tire manufacturer’s identification
mark
Ti r e s i z e c o d e
Manufacturer’s optional tire type
code (3 or 4 letters)
Manufacturing week
Manufacturing year
*: The DOT symbol certifies that the tireconforms to applicable Federal Motor
Vehicle Safety Standards.
Typical DOT and Tire Iden tification Number (TIN)
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784
GS350_OM_OM30D41U_(U)
8-1. Specifications
■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
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GS350_OM_OM30D41U_(U)
7858-1. Specifications
8
Vehicle specifications
Bead
Sidewall
Shoulder
Tread
Belt
Inner liner
Reinforcing rubber
Carcass
Rim lines
Bead wires
Chafer
Tire section names
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786
GS350_OM_OM30D41U_(U)
8-1. Specifications
This information has been prepared in accordance with regulations issued
by the National Highway Traffic Safety Administration of the U.S. Depart-
ment of Transportation.
It provides the purchasers and/or prospective purchasers of Lexus vehi-
cles 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 conform to Federal Safety Require-
ments 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 controlle d conditions on a specified govern-
ment 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 actual conditions of their
use. Performance may differ significantly from the norm due to variations in
driving habits, service practices and differences in road characteristics and cli-
mate.
■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 controlled conditions on sp ecified 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

GS350_OM_OM30D41U_(U)
7878-1. Specifications
8
Vehicle specifications
■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 conditio ns on a specified indoor labora-
tory test wheel.
Sustained high temperature can cause th e material 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 performance 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, underinflation, or excessive loading, either separately or in
combination, can cause heat buildup and possible tire failure.

788
GS350_OM_OM30D41U_(U)
8-1. Specifications
Glossary of tire terminology
Tire related termMeaning
Cold tire inflation pres-
sureTire pressure when the vehicle 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 pres-
sureThe maximum cold inflated pressure to which a tire
may be inflated, shown on the sidewall of the tire
Recommended inflation
pressureCold tire inflation pressure recommended by a man-
ufacturer
Accessory weight
The combined weight (in excess of those standard
items which may be replaced) of automatic transmis-
sion, 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 vehicle 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 vehicle
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 distributionDistribution 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
considered in curb weight or accessory weight,
including heavy duty brakes, ride levelers, roof rack,
heavy duty battery, and special trim
RimA metal support for a tire or a tire and tube assembly
upon which the tire beads are seated

GS350_OM_OM30D41U_(U)
7898-1. Specifications
8
Vehicle specifications
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 designated seating capacity
Vehicle maximum load on
the tireThe 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 normal load on
the tire
The load on an individual tire that is determined by
distributing to each axle its share of curb weight,
accessory weight, and normal occupant weight (dis-
tributed in accordance with Table 1
* below), and
dividing by two
We a t h e r s i d eThe 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 separationA breakdown of the bond between components in
the bead
Bias ply tire
A pneumatic tire in which the ply cords that extend to
the beads are laid at alternate angles substantially
less than 90 degrees to the centerline of the tread
CarcassThe tire structure, except tread and sidewall rubber
which, when inflated, bears the load
ChunkingThe breaking away of pieces of the tread or sidewall
CordThe strands forming the plies in the tire
Cord separationThe parting of cords from adjacent rubber com-
pounds
CrackingAny parting within the tread, sidewall, or innerliner of
the tire extending to cord material
Tire related termMeaning

790
GS350_OM_OM30D41U_(U)
8-1. Specifications
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
GrooveThe space between two adjacent tread ribs
InnerlinerThe layer(s) forming the inside surface of a tubeless
tire that contains the inflating medium within the tire
Innerliner separationThe parting of the innerliner from cord material in the
carcass
Intended outboard side-
wall
(a) The sidewall that contains 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 side-
wall of the tire, or
(b) The outward facing sidewall of an asymmetrical tire that has a particular side that must always
face outward when mounted on a vehicle
Light truck (LT) tire
A tire designated by its manufacturer as primarily
intended for use on lightw eight trucks or multipur-
pose passenger vehicles
Load ratingThe maximum load that a tire is rated to carry for a
given inflation pressure
Maximum load ratingThe load rating for a tire at the maximum permissible
inflation pressure for that tire
Maximum permissible
inflation pressureThe maximum cold inflation pressure to which a tire
may be inflated
Measuring rimThe rim on which a tire is fitted for physical dimension
requirements
Open spliceAny parting at any junction of tread, sidewall, or
innerliner that extends to cord material
Outer diameterThe overall diameter of an inflated new tire
Tire related termMeaning