Widest rims on a 2014 C220 or 5x120 with adaptors

[Craiglxviii]

not slamming the car, just switching to something different and 19's

Presuming that 19" is bigger than what you have already, your ride quality will reduce as you will have 1" less of tyre sidewall height to cushion you from the bumps and potholes that our Third World roads are full of nowadays.