[Proghound]

Larger discs are fine with 17"s, I'm running the 17" original rims from my old C70 on the current one and that's an auto. BTW I'm fairly sure I've read that there's sufficient clearance even with the 16" if you were to be looking at a set of Castulas (only fitted to the lowest trim S/ES models as standard, but the best choice for winter wheels).

The other thing that is different on the C70 from the C30/S40/V50, is tyre sizes. On the C70, 17" wheels were specced with 235/45 tyres, whereas the most common 17" on the other cars is 205/50. Tip: the C70 handbook shows that (possibly only in some markets) there was also a 215/50x17 option, which is less than 0.5% difference in the rolling radius from 235/45 and should therefore be (a) cheaper and (b) OK with insurers. I ran that size on the winter wheels I traded the old C70 in with.