Accessory weight
The combined weight (in excess of those standard items which may be replaced) of automatic trans-mission, 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 inflated, 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 extending 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 miles (kilometers) at low speeds in the 3 hour period before the tire pressure is measured or adjusted.
Curb weight
The weight of a motor vehicle with standard equipment including the maximum capacity of fuel, oil, and coolant, air conditioner, and additional weight of optional equipment.
Extra load tire
A tire designed to operate at higher loads and at higher inflation pressures than the corresponding standard tire.
Gross Axle Weight Rating (GAWR)
The load-carrying capacity of a single axle system, measured where the tire contacts the ground.
Gross Vehicle Weight Rating (GVWR)
The maximum loaded weight of the vehicle.
Groove
The space between 2 adjacent tread ribs.
