I'm just curious what the absolute widest you could go for the front and back of a g37s and what offset would be the lowest that could be possible along with what tires would fit best on the wheels. Thanks.

 

You will probably get the "go therefore and search" comments on this one so buck up.

There is no single answer to your question. Size of the wheels, camber setting, offset, care if you rub?, willing to trim the bumper bracet and wheel well lining?, etc all factor into the answer. You really need to read up some and then ask more specific questions.