TIRE PARTS GLOSSARY
Rubber-coated layers of steel, fiberglass, rayon, and other materials located between the tread and plies, crisscrossing at angles, hold the plies in place. Belts provide resistance to punctures and help treads stay flat and in contact with the road.
Sipes are special treads within the tread that improve traction on wet, dirty, sandy, or snowy road surfaces.
The portion of the tire that comes in contact with the road.
The spaces between two adjacent tread ribs are also called tread grooves. These allow water to escape effectively.
The outer edge of the tread that wraps into the sidewall area.
The sidewall of the tire protects cord plies and features tire markings and information such as tire size and type.
G. Inner Liner
This is the innermost layer of a tubeless tire that prevents air from penetrating the tire.
READING A TIRE SIDEWALL
A. Tire Size
The tire size is a combination of letters and numbers used to define a particular tire’s width, height, aspect ratio, construction type, and service description.
B. Maximum Cold Inflation Load Limit
This information tells the maximum load that can be carried and the maximum pressure needed to support that load. Please note that you should always inflate your tires to the pressure noted on the tire pressure placard (typically located on your driver door frame) or in your Owner’s Manual. To find more information on tire pressure and inflation, click here.
C. Tire Performance Criteria Specification (TPC Spec)
Most OE tires designed to GM’s specific tire performance criteria have a TPC spec code molded onto the sidewall. GM’s TPC specs meet or exceed all federal safety guidelines.
D. Winter Tire Symbol
Tires designed specifically for use in winter conditions (snow, slush, ice, and low temperatures) feature a three-peak mountain snowflake symbol.