I have my car dropped about 1 1/2"..and the 315 nittos do not rub. I actually have a pic of the space between the quad shock and the tire for reference. its close, but doesn't rub. No "rolling" needed either. Thats just my car however. g/l
315's arent that much bigger than the 275, HOWEVER, they are a necessity IMO for looks when you get a 10.5 rim. I have never seen a 275 on a 10.5 rim before, but judging by my 315 on there now, it wouldn't look right..here are some pics
315 on rim (notice how far the 315 extends from the wheel, then think about the 275, check the 315 to 275 comparison pic below
quad shock and 315 nitto clearance..
315 to 275 comparison
this pic has the 275 on the 17x9 and the 315 on the 17x10.5..think about that 275 on that 10.5
again...g/l post em when you get em