2011 Lexus IS 350 Owners Manual - Page 526

6-1. Specifications Tire related term Ply separation Meaning A parting of rubber compound between adjacent plies 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 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 A tire designed to operate at higher loads and at higher inflation pressures than the corresponding standard tire The linear distance between the exteriors of the sidewalls of an inflated tire, excluding elevations due to labeling, decoration, or protective bands That portion of a tire between the tread and bead The parting of the rubber compound from the cord material in the sidewall A tire that attains a traction index equal to or greater than 110, compared to the ASTM E-1136 Standard Reference Test Tire, when using the snow traction test as described in ASTM F-1805-00, Standard Test Method for Single Wheel Driving Traction in a Straight Line on Snow-and Ice-Covered Surfaces, and which is marked with an Alpine Symbol ( on at least one sidewall ) Pneumatic tire Radial ply tire Reinforced tire Section width Sidewall Sidewall separation Snow tire Test rim Tread 538 The rim on which a tire is fitted for testing, and may be any rim listed as appropriate for use with that tire That portion of a tire that comes into contact with the road