I don't think the steels vary from the alloys as only one set of figures is ever shown on
various tables etc online:
http://www.alloyguide.com/Citroen.phpModel: XM
Year: 89 to 00
PCD: 5x108
Offset: 35 to 38
Bore: 65.1
Alfa 166 rims are the same spec fitment. What do you have planned exactly!?
I do like the flat aerodynamic trims you have on your car already TBH!!
Andrew