I want to get the widest tire I can fit under there. Tell you what I did have and they fit aokay. I have 205/40-17'6 on ther now with ABT 24's 17x7.5. I've had 225/40-16's Yokahoma A520's on too. They fit great too. So I'm thinking I could go to a 215/40-17. What you guys think. Does anyone have this size on?