Originally Posted by eganders
Just thinking about the same thing. I'd like to know as well. At least on the front wheels, it looks lit 17' is about as small as will fit over the brakes in the front - and even then you need to be careful. If you did that, and then put on some softer springs, I'm sure it would help.
I did some checking and 225 45 17's and 255 40 18's would give the same overall size tire but would give a little more side wall which will have the effect of lowering the spring rate a little. These size tires also open up other possibilities like V rated tires which will ride smoother and cost less than the Z rated tires. By going with 17 and 18 inch wheels and the above tires, I will still have the stock raked look. Now I just have to find the perfect wheels. I also think that 16's will work. the brakes aren't that big and the SLK comes with 16's.