I'm wanting to get a set of new wheels and tires for my car, and want to go ahead and get wide rear wheels in preparation for huge power.

So....what is the widest practical tire you can run in the factory wheel wells? Practical meaning no rubbing under normal conditions with a stiff suspension except for maybe a huge bump.

What kind of wheel offset is optimal for fitting a wide tire/wheel?
I want to get a set of the Weld Pro Star XPs, if they make them in the right size.

I want to run 17"s front and rear on the street every day then have 15"s on the rear for track days.

Thanks guys...