Accessory weight
The combined weight (in excess of those standard items which may
be replaced) of automatic transmission, electro-mechanical 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).
Aspect ratio
The ratio of sidewall height to tire width, expressed as a percentage.
A number of 70 (0.7:1 or 70%) or lower indicates a low-profile tire with
a shorter sidewall for improved steering response and better overall
handling on dry pavement.
Bead
The part of a tire made of steel wires, wrapped or reinforced by ply
cords, with the shape and structure to ensure proper fit to the wheel
rim.
Bead separation
A breakdown of the bond between components in the bead.
Carcass
The tire structure, except tread and sidewall rubber which, when in-
flated, bears the load.
Chunking
The breaking away of pieces of the tread or sidewall.
Cord
The strands of material forming the plies in the tire.
Cord separation
The parting of cords from adjacent rubber compounds.
Cracking
Any parting within the tread, sidewall, or inner liner of the tire extend-
ing to cord material.
Cold tire inflation pressure
The tire pressure recommended by the vehicle manufacturer for a tire
of a specified size that has not been driven for more than a couple of
Normal occupant weight
Means 150 lbs (68 kilograms) times the number of occupants seated
in the vehicle up to the total seating capacity of your vehicle.
Occupant distribution
The placement of passengers in a vehicle.
Outer diameter
The diameter of a new, properly inflated tire.
Overall width
Total width measured at the exterior sidewalls of an inflated tire, in-
cluding the additional width of labeling, decorations, or protective
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 pounds or less.
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, pro-
vides the traction and contains the gas or fluid that sustains the load.
Production options weight
The combined weight of installed regular production options weighing
over 5 lbs (2.3 kg) more than the standard items they replace, and not
previously considered as curb weight or accessory weight. These
include, for example, heavy-duty brakes, ride levelers, roof rack,
heavy-duty battery, and special trim.
Radial ply tires
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.