Tires are designed to give many thousands of miles of service, but they must be maintained in order to get the maximum benefit from them.

Glossary of tire terminology

• Tire label: A label showing the OE (Original Equipment) tire sizes, recommended inflation pressure and the maximum weight the vehicle can carry.
• Tire Identification Number (TIN): A number on the sidewall of each tire providing information about the tire brand and manufacturing plant, tire size and date of manufacture. Also referred to as DOT code.
• Inflation pressure: A measure of the amount of air in a tire.
• Standard load: A class of P-metric or Metric tires designed to carry a maximum load at 35 psi [37 psi (2.5 bar) for Metric tires]. Increasing the inflation pressure beyond this pressure will not increase the tire’s load carrying capability.
• Extra load: A class of P-metric or Metric tires designed to carry a heavier maximum load at 41 psi [43 psi (2.9 bar) for Metric tires].

Increasing the inflation pressure beyond this pressure will not increase the tire’s load carrying capability.

• kPa: Kilopascal, a metric unit of air pressure.
• PSI: Pounds per square inch, a standard unit of air pressure.
• Cold inflation pressure: The tire pressure when the vehicle has been stationary and out of direct sunlight for an hour or more and prior to the vehicle being driven for 1 mile (1.6 km).
• Recommended inflation pressure: The cold inflation pressure found on the Safety Compliance Certification Label or Tire Label located on the B-Pillar or the edge of the driver’s door.
• B-pillar: The structural member at the side of the vehicle behind the front door.
• Bead area of the tire: Area of the tire next to the rim.
• Sidewall of the tire: Area between the bead area and the tread.
• Tread area of the tire: Area of the perimeter of the tire that contacts the road when mounted on the vehicle.
• Rim: The metal support (wheel) for a tire or a tire and tube assembly upon which the tire beads are seated.