Tyre terminology
The following is a list of tyre-related terminology.
| Tyre information placard | A plate that specifies OE tyre size (original equipment), recommended tyre pressure and the maximum weight the car can carry. |
| Tyre identification number (TIN) | A number on the sidewall of each tyre with information about tyre brand and manufacturing plant, tyre size and date of manufacture. |
| Inflation pressure | A measurement of how much air is in the tyre. |
| Standard load | A class of P-metric or metric tyres designed for a maximum load at 35 psi1. The load-bearing capacity of the tyres does not increase if the tyre pressure is increased above this pressure. |
| Extra load | A class of P-metric or metric tyres designed for a heavier maximum load at 41 psi2. The load-bearing capacity of the tyres does not increase if the tyre pressure is increased above this pressure. |
| kPa | Kilopascal, a metric unit for air pressure. |
| psi | Pound per square inch, a standard unit for air pressure. |
| B-pillar | The beam on the side of the car behind the driver's door. |
| Bead area of the tyre | The tyre's surface area next to the wheel rim. |
| Sidewall of the tyre | The surface area between the base of the tyre and the tread. |
| Tread area of the tyre | The surface area of the tyre's circumference that has contact with the road when the tyre is fitted to the car. |
| Rim | Metal support (wheel) for a tyre or tyre and inner tube unit against which the base of the tyre seals. |
| Maximum load rating | A figure that specifies the maximum load in pounds and kilograms that the tyre can carry. This classification is made by the tyre manufacturer. |
| Maximum permissible inflation pressure | The maximum tyre pressure that the tyre should ever be subjected to. This limit is specified by the tyre manufacturer. |
| Recommended tyre inflation pressure | Tyre pressure, specified by Volvo, based on the type of tyres fitted to a car on delivery. This information is available on the tyre plate on the B-pillar on the driver's side and in the tyre pressure table. |
| Cold tyres | Tyres are considered cold when they have the same temperature as the surrounding air. This temperature is normally reached when the car has been parked for at least three hours. |