you have two suspensions on your car.

Springs/ Shocks
Tire sidewall. In general terms the shorter the tire sidewall, the stiffer it is. This is not always the case, however. Tire designs vary.

I have sport springs, Bils sport shocks, 16 wheels and 215/55 tires. The ride is perfect, imo. the w124 is a VERY smooth cruiser, with new suspension. Therefore, if you want to improve the look and handling, 16's will do that and not hurt your ride.

Now when you get to 45 series tires on 18" rims, that can be rough, annoyingly rough.

If you like the look of your car and its wheels, start with replacing the shocks. Boges will give you factory ride, Bil HD will stiffen that up quite a bit.

__________________
The Wolf: That's thirty minutes away. I'll be there in ten.