The car has an approval for the complete vehicle. This means that certain combinations of wheels (wheel rims) and tyres are approved.
The dimensions are stated on all car tyres. Example of designation:235/45R17 97W.
| 235 | Tyre width (mm) |
| 45 | Ratio between tyre wall height and tyre width (%) |
| R | Radial ply |
| 17 | Rim diameter in inches (") |
| 97 | Codes for the maximum permitted tyre load, tyre load index (LI) |
| W | Speed rating for maximum permitted speed, speed rating (SS). (In this case 270 km/h.) |