How bad are 19's in the winter?
plus, if you have real nice wheels, you might not want it in the snow anyways...
Even if you head to the tire rack, they seem to recommend 225/55-17s for an S-430 in a winter package (Winter Sports, Blizzaks, X-Ice, etc). I'm sure it *can* be done, but the question I think is whether or not it's practical, even with 4-matic...

I think it also depends on whether you have another set of wheels hanging around or if you're planning to buy a whole set... I don't think it's a good idea to keep mounting and re-mounting summer/winter/summer/winter tires on the same rims depending on the season.


