What tyres should i use, how big can i go?

Guest
Hi all, need sum new tyres, lookin at F1's as they're great.

I have the standard 5 spoke audi alloys on the a4. Stayin with these as i like the look and cant afford new wheels.

At the moment i think its on 205/50/16's

Can i go marginally wider and, lower profile?

Saayyy 215/45/16??

What are others running?