225 on 6.5" wheels look a bit bulgy, IMO, and also will not perform as well as the same tire mounted on 7.5" wheels.

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First of all, when you increase the wheel diameter, in order to maintain the overall diameter you must decrease the side wall height, thus go to a lower profile. This means less rubber and thus less ride comfort.




Less sidewall does not necessarily mean less ride comfort, but you are answering your own question. Less sidewall is, in effect, a stiffening of the suspension, which people do for what should be obvious reasons. If ride comfort is your main point, don't do it.

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If you go to wider tires, you should lower further the tire profile which gives you this not so aesthetic "bike look" with much less ride comfort.




I am somewhat with you, except that I think 17 inchers on this car are about perfect. I think you can go too far, aesthetically, with big wheels/thin rubber, but 17 is well within the "good taste" range.

Also, wider tires need a lower aspect ratio to keep the same sidewall height. The aspect ratio is a percentage of section width. Get it?

Finally, a tire with a lower aspect ratio puts more of it's rubber on the road. Think of a big, 70-series tire. Section width is measured at the widest point of those bulging sidewalls. Compare those sidewalls to the width of the tread. Now look at a "low-profile" tire. See how close the section width is to the tread width?

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I can't understand why some SVT's owners change their wheels from 16" to 17" and more.




Well, if chosen carefully, larger wheels--especially if also wider--net you better and more precise turn-in, and higher overall grip, coupled with great looks, at a slight penalty in ride comfort in some cases. Even if it's not your bag, I hope you can understand that.

Function before fashion. '96 Contour SE "Toss the Contour into a corner, and it's as easy to catch as a softball thrown by a preschooler." -Edmunds, 1998