Tire size for '01 A4

[Lee Levitt]

I'm purchasing an '01 A4 1.8t quattro avant with sport suspension. The car
currently has 16" wheels. I'm going to upgrade to 17", am wondering what
size tire will fit.
 
I think the 225/45/17 is the stock size on the B5 S4, not that this is a
necessarily useful datapoint.
 
I'd like to go to a 235/45/17...or even a 245/40/17.
 
Can anyone give me some guidance as to what will fit, using stock A4 17 x
7.5 wheels?
 
Thanks!
 
Lee