[OminouSS]

So let me further complicate this answer. Yeah, you can run 3mm + additional. There is room under most scenarios, just not much. But even the tire brand will make or break that. Michelins, for example have a more tapered tire with the tread patch being more narrow than the sidewall. I would not push the positive offset much on the front. There seems to be much more room on the negative side (or less +) of the mounting surface. The back is the exact opposite. You cannot go too much wider on stock offset nor can you build in negative offset unless you plan to reduce the diameter. Wish this could be simpler. GM built a very tight fit to get those wider tires for us. I'd love to run 305's squared...if they had the right rubber selection for me. Since they do not, the next best squared setup I can do is 285/35R19's. Still not bad.