Has anyone tried this? I just got the idea since my front two are messed up. I wonder how 275's or 285's on the stock 19x9's on front and back would look.

 

I actually considered doing that as well but with IPL rims since I have an IPL. But it's just too hard to find two rear IPL wheels and the ones that are for sale don't check the bang for the buck box. For a bit more $$$, I can go with decent aftermarket wheels that are even wider.

But with the OEM S wheels, they're far more prevalent and probably pretty inexpensive considering. Just make sure they clear the calipers. I never really understood why they didn't go with a square setup on the S and the IPL. We have the same front tire width as the 911 but it's engine is in the rear. With all that heft over the front, you'd think the engineers would have spec'd more front tire.

 

We should do like the import homies and put big fat meats on the front and space-saver spares on the rear. FWD FTW!

 

And if they're going to stagger why the F didn't they go w/ a real stagger????
A 1/2" stagger is nothing in terms of any difference in look/stance/ or handling differences. It's more of an annoyance at that point since you can't do a true 4 tire rotation and can't run much different tires sizes and still get a proper mount.
To the OP, I wouldn't run any wider than 275s, but 275s all around on 9s should look pretty nice.