I think one thing that can confuse many people is WheelYour installer is correct. All this boils down to a simple conclusion - keep your wheel width really close to your section width. If you want more performance, make them the same or even slightly larger on the wheel width. If you want cheaper wheels, less weight, less vulnerability to curb rash, you can make the wheel somewhat narrower than the section width.
As for speaking to looks, this is clearly an area where beauty is in the eye of the beholder. I personally love the look of wheels and tires where the the wheel width nails the section width on the nose - and the wider wheel makes the tire look wider, which I also like.
width is the measurement (inside the lip)..... measurement from outside lip to outside lip is about an inch more