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487 6-1. Specifications
6
Vehicle specifications
Tire related termMeaning
Normal occupant
weight150 lb. (68 kg) times the number of occupants
specified in the second column of Table 1
* that
follows
Occupant distributionDistribution of occupants in a vehicle as speci-
fied in the third column of Table 1
* below
Production options
weightThe combined weight of installed regular pro-
duction 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
Rim diameter
(Wheel diameter)Nominal diameter of the bead seat
Rim size designation Rim diameter and width
Rim type designationThe industry manufacturer’s designation for a
rim by style or code
Rim width Nominal 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
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488 6-1. Specifications
Tire related termMeaning
Vehicle normal load
on the tireThe load on an individual tire that is determined
by distributing to each axle its share of curb
weight, accessory weight, and normal occu-
pant weight (distributed in accordance with
Ta b l e 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 and that is
shaped to fit the rim
Bead separationA breakdown of the bond between components
in the bead
Bias ply tireA pneumatic tire in which the ply cords that
extend to the beads are laid at alternate angles
substantially less than 90 degrees to the cen-
terline 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
Cord The strands forming the plies in the tire
Cord separationThe parting of cords from adjacent rubber com-
pounds
CrackingAny parting within the tread, sidewall, or inner-
liner of the tire extending to cord material
CTA 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
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489 6-1. Specifications
6
Vehicle specifications
Tire related termMeaning
Extra load tireA tire designed to operate at higher loads and
at higher inflation pressures than the corre-
sponding standard tire
Groove The 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
sidewall(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
sidewall of the tire, or
(b)The outward facing sidewall of an asymmet-
rical tire that has a particular side that must
always face outward when mounted on a vehi-
cle
Light truck (LT) tireA tire designated by its manufacturer as prima-
rily intended for use on lightweight trucks or
multipurpose 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 per-
missible 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 diameter The overall diameter of an inflated new tire
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490 6-1. Specifications
Tire related termMeaning
Overall widthThe linear distance between the exteriors of
the sidewalls of an inflated tire, including eleva-
tions due to labeling, decorations, or protective
bands or ribs
Passenger car tireA tire intended for use on passenger cars, mul-
tipurpose passenger vehicles, and trucks, that
have a gross vehicle weight rating (GVWR) of
10,000 lb. or less.
Ply A layer of rubber-coated parallel cords
Ply separationA parting of rubber compound between adja-
cent plies
Pneumatic tireA mechanical device made of rubber, chemi-
cals, fabric and steel or other materials, that,
when mounted on an automotive wheel, pro-
vides the traction and contains the gas or fluid
that sustains the load
Radial ply tireA pneumatic tire in which the ply cords that
extend to the beads are laid at substantially 90
degrees to the centerline of the tread
Reinforced tireA tire designed to operate at higher loads and
at higher inflation pressures than the corre-
sponding standard tire
Section widthThe linear distance between the exteriors of
the sidewalls of an inflated tire, excluding ele-
vations due to labeling, decoration, or protec-
tive bands
SidewallThat portion of a tire between the tread and
bead
Sidewall separationThe parting of the rubber compound from the
cord material in the sidewall
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