i think my tC already has a pretty rough ride with the 17 inch rims. did you guys notice a big difference in ride roughness when you upgraded to the 18 inch rims because of the thinner tire?

 

aha not much difference. i'm on EMX super 7's now. the only difference is from that 45% to the 40% on the sidewall.

 

rim size does not affect ride quality. your suspension travels the same amount.

 

HAHA rim size does not effect ride quality but the amount of rubber on the rim definitely does. A bigger rim usually means less rubber but in this case I doubt 1 inch is really going to make a noticeable difference.

 

If you stick with a 45 sidewall on the tires, it won't be noticable. If you drop to a 40 or even 35 sidewall, you'll feel it some. When I went from a 65 sidewall to a 40 on my old car, I definitly felt a harsher ride. Depends on your springs to. If you have a soft spring rate, you won't feel it much. Now, if you have coilovers and are slammed down low, you'll feel that.

 

my ride actually got better going form 17s with 45 sidewalls to 18s with 40 sidewall,since i went wider tire for the 18s the sidewalls stayed prety much the same height as the 17s were,but more tire to the ground seems to have softened up how it rides a bit.