I installed new 17 x 7 1/2 rims on my Contour SE(from 15") with 215/45ZR17 Firestone Firehawks. I have noticed no ill effects from the change. What I have noticed with the suspension upgrades I made along with the tire/wheel combo is a car that handles much better than before. I also have room for brake upgrades now if I wish to do so. The shorter, stiffer sidewall on a lower profile tire does help handling by decreasing sidewall flex, but the rubber compound on a tire can increase coefficient of friction. That means the compound is softer and provides greater contact surface with the pavement . . . more contact, more traction and handling. It's also good if the same tire is designed for wet traction as well. Hope this helps.
