Depends on what state you are in.
In WA, you can only go 1 inch above standard..........so that makes a maximum of 7". The front and rear wheels have to be exactly the same size. They normally allow about a 10% difference in front/rear tyre sizes. ie: 265 rear and 245 front. (but 265's will pop off a 7" rim!!)
The Fairmont and ESP mags were 7" wide so I say +1 and there's my 8, if they ask questions.
I just took my 15x11's off