09 MS3 Winter Tire sizing
 

So I'm looking for a snow tire and rim combo on Craigslist for my new MS3 and I came across a pretty good bargain but I'm not sure about the tire sizing. I went to Tire Rack and they had 205/60-16 215/55-16 as compatible tire sizes. The one that I'm looking at is a 205/55-16. Would this size fit my car?

If you have the money, definitely get a second set of rims and get a dedicated set of winter tires. As for sizing, the 205 vs 215 should fit, but your speedo may be off a bit. Use a calculator such as http://www.1010tires.com/TireSizeCalculator.asp or http://www.tiresizecalculator.info/ to see how much the speedo will be off.

As a note - if you don't know the 205 is mm width of the tread, the 55 is an aspect ratio (hright of the tire is 55% of the 205mm width) and the 16 is the rim diameter. That's all explained on tire sites as well.

That being said, you can figure out some of the dimensions on your own to make sure the tire won't hit stuff. But I think the options for tire sizes are in the owners manual.

My M3 has 17" rims stock and I got a set of 16" rims and tires for winter off of 1010tires. I then got a set of used tire pressure monitors for the second set of rims. All done with tires mounted and everything was under ~$900 and the TPMS works fine with either set of rims.
Though I think tire prices are up, but you should be good if you can spend a grand on the whole setup.

Good luck.