SatansReverence
Hipster Princess
The engine can display different front and rear wheel sizes, (wheel diameter and width), provided you fit aftermarket rims, but it cannot display different wheel offsets, (distance from the hub to the wheel centerline).
This is most apparent on, but certainly not limited to, race cars:
The early screenshots of the P1 suggest this limitation is still in FM5, or at least was at the time they were taken, as BADNED has noted that the shots were from an early build.
It was talked about as a "feature" which really doesn't bode well...