Load rating (code)
The maximum load that a tire is rated to carry for a given inflation pressure. You may not find this information on all tires because it is not required by law.
Maximum load rating
The load rating for a tire at the maximum permissible inflation pressure for that tire.
Maximum loaded vehicle weight
The total of:
x Curb weight
x Accessory weight
x Vehicle capacity weight
x Production options weight
Maximum (permissible) inflation pressure
The maximum cold inflation pressure to which a tire may be inflated. Also called “maximum inflation pressure.”
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, including 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, 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 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.
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.
Speed rating (letter code)
A standardized letter code indicating the maximum speed at which a tire is designed to be driven for extended periods of time. The ratings range from 93 mph or 150 km/h (“P”) to 186 mph or (300 km/h) “Y”.
The speed rating letter code, where applicable, is molded on the tire sidewall ⇒ Tire labeling. You may not find this information on all tires because it is not required by law.
Tire Pressure Monitoring System (TPMS)
A system that detects when at least one of a vehicle's tires is underinflated and illuminates a low tire-pressure warning light.
Tread
The portion of a tire that normally touches the road.