Refer to the following list for detailed definitions of the terms found in the tyre description:

Air Pressure

The amount of air inside the tyre pressing outward on the tyre. Air pressure is expressed in pounds per square inch (psi) or kilopascal (kPa).

Accessory Weight

The combined weight of optional accessories. Some examples of optional accessories are automatic transmission, power seats, and air conditioning.

Aspect Ratio

The relationship of a tyre’s height to its width.

Belt

A rubber coated layer of cords located between the plies and the tread. Cords may be made from steel or other reinforcing materials.

Bead

The tyre bead contains steel wires wrapped by steel cords that hold the tyre onto the rim.

Bias Ply Tyre

A pneumatic tyre in which the plies are laid at alternate angles less than 90 degrees to the centerline of the tread.

Cold Tyre Pressure

The amount of air pressure in a tyre, measured in pounds per square inch (psi) or kilopascals (kPa) before a tyre has built up heat from driving.

Kerb Weight

The weight of a motor vehicle with standard and optional equipment (including the maximum capacity of fuel, oil, and coolant), but without passengers or cargo.

GVWR

Gross Vehicle Weight Rating.

GAWR FRT

Gross Axle Weight Rating for the Front axle.

GAWR RR

Gross Axle Weight Rating for the Rear axle.

Intended Outboard Sidewall

The side of an asymmetrical tyre that must always face outward when mounted on a vehicle.

Kilopascal (kPa)

The metric unit for air pressure.

Light truck (LT) tyre

A tyre designated by its manufacturer as primarily intended for use on lightweight trucks or multipurpose passenger vehicles.

Load rating

The maximum load that a tyre is rated to carry for a given inflation pressure.

Load Index

An assigned number ranging from 1 to 279 that corresponds to the load carrying capacity of a tyre.

Maximum Inflation Pressure

The maximum air pressure to which a cold tyre may be inflated. The maximum air pressure is molded onto the sidewall.

Maximum Load Rating

The load rating for a tyre at the maximum inflation pressure for that tyre.

Maximum Loaded Vehicle Weight

The sum of the kerb weight, accessory weight, vehicle capacity weight, and production options weight.

Normal Occupant Weight

The number of occupants a vehicle is designed to seat multiplied by 68 kg (150 lb).

Occupant Distribution

Designated seating positions.

Outward Facing Sidewall

The side of an asymmetrical tyre that faces outward when mounted on a vehicle. The outward facing sidewall bears white lettering or manufacturer, brand, or model name moldings that are higher or deeper than the same moldings on the inner facing sidewall.

Passenger (P-Metric) Tyre

A tyre used on passenger cars and some light duty trucks and multipurpose vehicles.

Ply

A layer of rubber-coated parallel cords.

Pneumatic tyre

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.

Production options weight

The combined weight of installed regular production options weighing over 2.3 kg (5 lb) more than the standard items that they replace, not previously considered in kerb weight or accessory weight. Examples include heavy duty brakes, ride levelers, roof rack, heavy duty battery, and special trim.

Recommended Inflation Pressure

The vehicle manufacturer’s recommended tyre inflation pressure, shown on the tyre placard.

Radial Ply Tyre

A pneumatic tyre in which the ply cords that extend to the beads are laid at 90 degrees to the centerline of the tread.

Rim

A metal support for a tyre upon which the tyre beads are seated.

Sidewall

The portion of a tyre between the tread and the bead.

Speed Rating

An alphanumeric code assigned to a tyre indicating the maximum speed at which the tyre can operate.

Traction

The friction between the tyre and the road surface (the amount of grip provided).

Tread

The portion of a tyre that contacts the road.

Treadwear Indicators

Narrow bands, sometimes called “wear bars,” that show across the tread of a tyre when only 1.6 mm (1/16 inch) of tread remains.

UTQGS

Uniform Tyre Quality Grading Standards, a tyre information system that provides consumers with ratings for a tyre’s traction, temperature, and tread wear. Ratings are determined by tyre manufacturers using government testing procedures. The ratings are molded into the sidewall of the tyre.

Vehicle Capacity Weight

The weight of the designated seating positions multiplied by 68 kg (150 lb) plus the rated cargo and luggage load.

Vehicle Maximum Load on the Tyre

The load on an individual tyre due to kerb and accessory weight plus the maximum occupant and cargo weight.

Vehicle Normal Load on the Tyre

The load on an individual tyre, determined by distributing to each axle its share of the kerb weight, accessory weight, and normal occupant weight and dividing by 2.

Vehicle Placard

A label permanently attached to a vehicle showing the original equipment tyre size and recommended inflation pressure.