what year is it? you can usually find stock rim width or other dimensions if you go to an online tire/wheel store and search for the specific model. it will display your stock sizes and aftermarket options that fit.I know it's a dumb question, and yes I have looked for the answer and was unable to find out exactly what I needed to know. I've got a base v6 Mustang with 17 inch wheels and need to know what the rim width is. Also is the standard wheel design available in a 18 inch wheel?