Glossary “tire life expectancy” Definition:
Expected service life of a tire, based on its tread wear rating and uniform tire quality grading.

Glossary “tire inflation label” Definition:
A label required by federal law and is usually placed on the inner glovebox door or on the a door post.

Glossary “tire inflation” Definition:
Air pressure inside the tire, measured in pounds per square inch (psi) or kiloPascal (kPa), checked when tire is cool or has been driven less than one mile.

Glossary “tire function” Definition:
1). To cushion the vehicle ride to provide a comfortable ride for the occupant; reduces jolts to the vehicle caused by road irregularities. 2). To support the vehicle weight. 3). To develop traction to drive and steer the vehicle under a wide variety of road conditions. 4). To contribute to the directional stability of the vehicle, and absorb all the stresses of accelerating, braking, and centrifugal force in turns.

Glossary “tire free diameter” Definition:
The free diameter of a tire is the distance of a horizontal line through the center of the spindle and wheel to the outer edges of the thread.

Glossary “tire design” Definition:
Three basic tire construction designs are based on the arrangement of the body plies: bias, belted radial, and belted bias. A bias-ply tire is constructed with the plies arranged on a bias crossing each other. A belted radial-ply tire is constructed with plies that run at right angles to the circumference of the tire. A belted bias-ply tire is constructed with reinforcing belts beneath the tread section.

Glossary “tire deflection” Definition:
Difference between the free diameter (unloaded) and the rolling diameter (loaded) of the tire.

Glossary “tire contact area” Definition:
The footprint, patch, or patch area of the tire that is in contact with the road surface when the tire is supporting the vehicle weight.

Glossary “tire construction” Definition:
Tire construction design has two wire beads, bead filler, liner, steel reinforcement in the sidewall, sidewall with hard side compound, rayon carcass plies, steel belts, jointless belt cover, hard under-tread compound, and hard high-grip tread compound.

Glossary “tire concentricity” Definition:
Condition where the plies and/or belts are not level across the tire tread and are somewhat cone shaped. This causes a pull to one side as the car is driven straight ahead if the tires are on the front of the vehicle.

Glossary “tire coding” Definition:
Information required by federal legislation to be placed on all tires, such as: manufacturer and tire name, size designation, maximum load-carrying characteristics, limit, and range, a ten-digit DOT serial number indicating where and when it was made, and the letter A, B, or C, indicating conformity to a uniform tire quality grading system.

Glossary “tire changer” Definition:
Machine for quickly dismounting and mounting tires on and off of wheels.

Glossary “tire chain” Definition:
Specialty chains which may be placed over the tires to improve traction when driving on ice or snow; typically used in emergency situations such as driving on snow-covered or ice-covered mountain roads.

Glossary “tire casing” Definition:
Layers of cord called plies on which the rubber tread is applied.

Glossary “tire carcass” Definition:
The plies that make up the underbody of the tire.

Glossary “tire black” Definition:
Black liquid dressing used to refresh the appearance of tires.

Glossary “tire belt” Definition:
Term used for belt.

Glossary “tire bead” Definition:
Term used for bead.

Glossary “tire balancing” Definition:
Procedure of using special equipment for identifying the lighter portions of a tire and adding weights until opposite tire sections weigh the same.