dnaruse

Are the alignment values for 18" wheels different that 17"? I put on 18" wheels and my alignment shop said that because I have stiffer sidewalls, the alignment values are different. They moved my alignment a little. Has anyone else had similar experiences?

Mark in Baltimore

No shop has ever mentioned the profile criteria to me.

Greg Fishman

If the ride height changes it might make a small change in your alignment. Not that most people would feel the difference when you are talking about tenths of a degree or less.

STLPCA

If this is for a street car as opposed to a fully race prepped car, I think your shop had some down time to fill. Many here (including me) regularly swap between 18" & 17" sets of street/track/winter tires w/o any alignment issues.

StatmanDesigns

There is a slight difference in alignment, but it is NOT related to the stiffness of the sidewall. When the alignment is measured it is based on the lip of the wheel and not the tire, since the wheel is a more reliable registration point. When you put a larger diameter wheel on, it will change the readings of the alignment since the edge of the wheel i now 0.5 inches further from the center.

Personally, I would ignore the difference, and get a new alignment whenever you would have if you kept the same wheels on.