Operating Guide

20
is higher or deeper than the same molding on the other
sidewall of the tire or 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
lightweight trucks or multipurpose passenger vehicles.
May be used on trailers.
Load rating: The maximum load that a tire is rated to
carry for a given ination pressure.
Maximum load rating: The load rating for a tire at the
maximum permissible ination pressure for that tire.
Maximum permissible ination pressure: The
maximum cold ination pressure to which a tire may
be inated.
Maximum loaded vehicle weight: The sum of curb
weight, accessory weight, vehicle capacity weight, and
production options weight.
Measuring rim: The rim on which a tire is tted for
physical dimension requirements.
Non-pneumatic rim: A mechanical device which,
when a non-pneumatic tire assembly incorporates a
wheel, supports the tire, and attaches, either integrally
or separably, to the wheel center member and upon
which the tire is attached.
Non-pneumatic spare tire assembly: A non-
pneumatic tire assembly intended for temporary use
in place of one of the pneumatic tires and rims that
are tted to a passenger car in compliance with the
requirements of this standard.
Non-pneumatic tire: A mechanical device which
transmits, either directly or through a wheel or wheel
center member, the vertical load and tractive forces
from the roadway to the vehicle, generates the tractive
forces that provide the directional control of the vehicle
and does not rely on the containment of any gas or
uid for providing those functions.
Non-pneumatic tire assembly: A non-pneumatic tire,
alone or in combination with a wheel or wheel center
member, which can be mounted on a vehicle.
Normal occupant weight: This means 68 kilograms
(150 lbs.) times the number of occupants specied in
the second column of Table I of 49 CFR 571.110.
Occupant distribution: The distribution of occupants
in a vehicle as specied in the third column of Table I
of 49 CFR 571.110.
Open splice: Any parting at any junction of tread,
sidewall, or innerliner that extends to cord material.
Outer diameter: The overall diameter of an inated
new tire.
Overall width: The linear distance between the
exteriors of the sidewalls of an inated tire, including
elevations due to labeling, decorations, or protective
bands or ribs.
Pin Weight: The downward force applied to the 5th
wheel or gooseneck ball, by the trailer kingpin or
gooseneck coupler.
Ply: A layer of rubber-coated parallel cords.
Ply separation: A parting of rubber compound between
adjacent plies.
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 uid that sustains the
load.
Production options weight: The combined weight
of those installed regular production options weighing
over 2.3 kilograms (5 lbs.) in excess of those 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.
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.
Recommended ination pressure: This is the
ination pressure provided by the vehicle manufacturer
on the Tire Information label and on the Certication /
VIN tag.
Reinforced tire: A tire designed to operate at higher
loads and at higher ination pressures than the
corresponding standard tire.
Rim: A metal support for a tire or a tire and tube
assembly upon which the tire beads are seated.
Tire Safety