16's will fit. There are plenty of people using Protege 5 and ES rims on their MSP for Winter/Track tires. I'm almost positive that a 15" rim will NOT clear the brake calipers. A 16" will fit fine.
There are people here successfully running 15 inch steel wheels with snows. I suppose you could have a clearance issue with certain 15 inch alloys wheels, but probably not.
The 16 inch wheels from the P5 fit. Many folks using them in winter here on their MSP's.
i was pretty sketchy looking into winter tires and rims. but after a few posts i decided to go with the fifteens. they actually fit i was suprised .
no problems so far!!!!
(bow) (wrc)