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 fluid that sustains the
load.
Production options weight
The combined weight of installed regular production options weighing over 5 lbs (2.3 kg) more then 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.
Recommended 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 miles (kilometers) at low speeds in the 3 hour period before the
tire pressure is measured or adjusted.
Reinforced tire
A tire designed to operate at higher loads and at higher inflation pressures than the corresponding
standard tire.
Rim
The outer edge of a wheel upon which the tire beads are seated.
Rim diameter
The nominal diameter of the wheel's tire bead seating surface. If you change your wheel size, to
wheels of a different diameter, you will have to purchase new tires to match the new wheels.
Rim size
Designation means rim diameter and width.
Rim type designation
The industry or manufacturer's designation for a rim by style or code.
Rim width
The nominal distance between wheel rim flanges.
Section width
The linear distance between the exteriors of the sidewalls of an inflated tire, excluding elevations due
to labeling decoration, or protective bands.
Sidewall
The portion of a tire between the bead and the tread.
Sidewall separation
The parting of the rubber compound from the cord material in the sidewall.
