335i

Need new wheels found a set of audi s6 wheels 20" how would they look on a car without sports package?

I have seen a few 19/20 they look okay but wanted your thoughts

tenspeed

They would look the same. The sport suspension makes the car sit about 20mm lower so there would be less of a gap at the top of the tire. Go for it.

snagitseven

I believe the overall wheel and tire diameter of the S6 is the same as the A6. If so, the gap between the fender and the wheel would be unchanged with the S6 wheels - larger wheel, lesser sidewall. If the S6 wheels and tires have a larger overall diameter, assuming they even fit on the A6, the gap would be still be essentially unchanged - the car would just sit a bit higher (and the soeedometer/odometer would be off). The only way to reduce the gap is to change the chassis suspension.
The OP would also have to check that the offset of the wheels is the same.

13c7a6

They should work fine. However, some of S6 wheels may have a more positive offset (+8?) to clear the bigger brakes. i.e. The center line of the wheel will move outward, which may give your car a more aggressive look