You're right about the sizing. I didn't separate my wording of tire and rims enough.
I will defer to a blurb I just Googled: http://elevatingsound.com/your-guide-to-getting-quiet-tires-...
I will defer to a blurb I just Googled: http://elevatingsound.com/your-guide-to-getting-quiet-tires-...
2. Smaller rims do not mean smaller tires. On a given car model, the outside diameter of the tire will be essentially fixed. If they have multiple wheel diameters, the tire sidewall height will change to accommodate the wheel diameter. Technically smaller-diameter rims actually mean larger tires.