Someone referenced my thread so I guess I can chime in.
My last set up was with the 17x9 +20 all around. Without being very low and not having natural camber kick the top of the wheel in, you're looking at a bit more poke than what I had up front. Same with the rear. The fronts will poke out a bit more due to the fact that the car narrows towards the front. If you are at stock height, you can get away with a thicker tire, yes. But the moment you bottom out the car/shocks, that tire will make contact with both front and rear. I was tucking the tire both front and rear with 205/40s on the 9s.
Currently, I have 17x8.5 +15. Now they poke 3mm less, but the stretch on my 205/40s aren't as much and I'm making a lot more contact on my sidewall in the rear, and this is even with rolled and slightly pulled fenders in the rear, which I need to pull just a tad bit more. But the damn double seam fender is a biiiiiiiiiiiitttttttcccccchhhhhhhhh.
Needless to say, if you don't plan on tucking and are at stock height with a decent sized tire, you don't have to roll the fenders front and back. Because regardless, the width of the tire means you will be making contact with the fender when you bottom out, no way around that due to the nature of how much poke there is with the wheel.
