A synthetic fiber that is, per weight, stronger than steel. Used in tire construction and provides excellent high-tensile strength-to-weight.

Aspect Ratio

An expression representing the height of the sidewall of a tire in terms of a percentage of tire's width.


When opposite sides of a tire's tread pattern are not identical.

Block Design

A tire tread pattern made of raised rubber-compound segments.


The individual, raised rubber-compound segments making up the tread of a tire.


That portion of a tire that is the foundation for the tread, belts, bead, and sidewall.


The structure of tire cords locked around wire beads.


A finishing strip of calendered fabric used to protect the tire's bead area from the rim.


The general term referring to the chemical formula for the tread material.

Drive Wheel(s)

The wheel(s) that provide the power or driving force for a vehicle.


The material used to fill the area above the bead between the outer and inner portion of the sidewall. Also used in enlarged form to stiffen the lower sidewall of a tire.


Circumferential channels between the tread ribs of a tire.


Loss of traction at high speeds caused by a wedge of water that lifts a tire off the road surface.

Light Truck Tires

Tires designed for off-the-road and on/off-the-road use on sport/utility, small commercial, and recreational vehicles.

Load Range

A method of rating a tire's load-carrying capacity (denoted by letters such as C, D, E etc.), with respect to its ply rating.


A term describing a tire with a low relative aspect ratio or series classification.

Metric Tire Size System

A tire sizing system using the section width (mm), aspect ratio, speed category, tire construction, and the rim diameter (inches). Example: 225/45R17.

P-metric System

A tire sizing system using the section width (mm), aspect ratio, type of tire construction and rim diameter (inches). Example: P215/60R16.


A layer of rubber-coated fabric or wire making up the tire casing.

Radial Tire

A tire built with casing plies that cross the crown at an angle of 90 degrees.


Parts of a tire tread pattern created by grooves that run circumferentially around the tire.


A numerical representation of a tire's aspect ratio; for example: 50 series.

Shoulder Blocks

Raised rubber-compound segments on the part of the tire tread nearest the sidewall.


Slits in the tire tread. Small cuts in the surface of the tread to improve traction.

Steel Belt

A belt material used in radial tires. Its high stiffness provides good handling and low treadwear.

Steer Wheel(s)

The wheel(s) that direct the course of a vehicle.

Stud Holes

Small cavities along a tire's tread designed to hold tire studs for increased traction on snow-covered surfaces.

Tire Profile

A term representing the portion of a tire measured as its aspect ratio or series.

Touring Performance Tire

A tire providing the ride comfort of a passenger car tire, yet possessing high-performance tire characteristics.

Trailer Wheel(s)

The wheel(s) of a trailer unit that neither provides power nor directs the course of a vehicle.

Tread Blocks

Raised rubber-compound segments on the outside visible part of a tire.


Uniform Tire Quality Grade. A government-mandated tire rating system based on a tire's performance in treadwear durability, traction, and temperature resistance. UTQG ratings are branded on a tire's sidewall.

Varied-Pitch Ratio

Variations in angles and sizes of a tire's tread elements that reduce ride noise levels.