BTFanC300

Hey so I bought a 2014 C300 as my first car ever a couple years back. I'm in Canada so the car came with a set of loose winter tires.
I'm getting sick of paying shops twice a year to get the tires off my rims and to put on the new ones, so I'd like to buy new rims. This is the first time I'm doing this so I have a couple of questions.
1) I know there are a few dimensions when it comes to rims, but which ones should I be worried about? I've been told to only care for the 5x112 PCD. Is there something else I should look out for that would new rims from fitting on my ties?
2) My car has a TPMS system that tells me when a tire is lacking air (doesn't give the measurement or tell me which tire it is though). Is this something I would have to add manually? Do most wheels already have this?

Thanks!

Plutoe

if you dont know your rim size any shop selling rims will know the correct size and yes you will have to purchase applicable TPMS sensors

Khan28

Your car does not have individual TPMS sensors. It measures wheel rotation instead hence the inability to see which tire needs air. You don’t have to worry about purchasing new sensors. If rim sizes and offsets are a concern then just look on classifieds for used OEM rims that are the same style as what you have. That way the bolt pattern and offset are correct.

AAIIIC

You need to pay attention to all of them. It's really not that hard, though, as there are a number of websites that will show you what specific wheels will fit on your car. Try www.tirerack.com or www.discounttiredirect.com, as a couple of examples.

If you're really worried about getting it wrong, then Khan28's answer is the easiest way to go - find some used OEM wheels from another W204.