I can fit 255's on the 8"wide stock rims on my 8, and that is on a car that has standard +50 tires. I can fit wider on the new +36 wheels I got now, as it moved the track in just the right amount that I won't need to roll the fenders, and it will still JUST miss the struts.
So if I can fit that on my car and you literally can't skid out after that, you won't need more on the much lighter 86