Bolt pattern diameter
The diameter of the conditional ring along which the mounting holes on the disk are located. Measured at the centers of the holes. This parameter must exactly match the corresponding wheel hub parameter. Together with the number of mounting holes, it forms a bolt pattern (PCD). The most popular values are 4 and 5 bolt discs, with corresponding PCD values:
4x98,
4x100,
4x108,
4x114.3,
5x100,
5x105,
5x108,
5x110,
5x112,
5x114.3,
5x115,
5x120,
5x130. For 6-bolt discs, the most common bolt pattern is
6x139.7.
Offset
Departure is the distance from the plane passing through the place where the wheel is attached to the hub, to the plane passing through the middle of the landing width. Positive overhang values mean that the hub is on the outside of the middle of the disc,
negative values mean that the hub is recessed "deep" into the wheel. For each car model, there is an individual departure value that is optimal for stability and controllability.
Centre bore diameter
The diameter of the centre hole must match the diameter of the centering lug on the vehicle hub. It may also be larger; then adapter rings are used to install the wheel.
