I just got a set of coupe wheels, just wondering what's the perfect size for it ? 235/45/18 all around? or 235/40/18 all around, i need to lower the car for about an inch, will 45 scratch the fender?? I don't have sport supension on my sedan.

Does 30mm offset even fit properly? The only picts ive seen are where the
wheels are sticking out of the fenders...