The dimensions are stated on all car tyres. Example of designation: 225/50R17 98W.
| 225 | Tyre width (mm) |
| 50 | Ratio between tyre wall height and tyre width (%) |
| R | Radial ply |
| 17 | Rim diameter in inches (") |
| 98 | 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 (168 mph).) |
The car has an approval for the complete vehicle with certain combinations of wheel rims and tyres.
Warning
19-inch wheels must never be used on cars that are not equipped with the R-Design or Sport chassis options. The use of 19-inch wheels on cars with standard chassis constitutes a safety risk, with a risk of vehicle damage, and it impairs the car's driving characteristics.