4829-1. Specifications
Occupant distributionDistribution of occupants in a vehicle as speci-
fied in the third column of Table 1
* below
Production options
weight
The 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
Rim
A 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 designated seating
capacity
Vehicle maximum load
on the tire
The load on an individual tire that is deter-
mined 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 deter-
mined by distributing to each axle its share of
curb weight, accessory weight, and normal
occupant weight (distributed in accordance
with Table 1
* below), and dividing by two
Tire related termMeaning
4859-1. Specifications
9
Vehicle specifications
Overall width
The linear distance between the exteriors of
the sidewalls of an inflated tire, including ele-
vations due to labeling, decorations, or protec-
tive bands or ribs
Passenger car tire
A tire intended for use on passenger cars,
multipurpose 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 separationA parting of rubber compound between adja-
cent plies
Pneumatic tire
A 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 tire
A 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 tire
A tire designed to operate at higher loads and
at higher inflation pressures than the corre-
sponding standard tire
Section width
The 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
Tire related termMeaning
