Focus "winter" wheels - different offsets?

[blackburn]

Hi all. My everyday car is an '06 Focus estate 2.0 Ghia with 16" alloy wheels. Now, I'm thinking of buying a pair of spare wheels to use on the front in snowy conditions, fitted with "winter" tyres (planning ahead, see?) I haven't checked whether the offset is marked on the 5 stud wheels, but before I do, does anyone know if all the Focus 16" wheels use the same offset? and are Mondeo wheels likely to be ok? There were a couple of used Mondeo steel wheels the other day on the 'bay which would have fitted the bill if they would fit.

Any sensible input would be appreciated, thanks.