That depends on the wheel offset and what you're buying the tire for. If it's just street use and visual, go with a low offset no less than +35 (fenders rolled) with a 225/40. If it's for track, a high offset around +50 (fenders still rolled) with a 245/40.
From what I've seen, these figures work. Where I got these figures from? Years of lurking and researching and learning from others trial and error. That's how I got the fitment I have today.
