I bought 15x8's with a 4.5" backspace and Mickey Thompson ET Streets 275/60/15 and the tires rubbed the entire frame (Especially at the the front). I tried a 5/16" spacer and the tire still hit the front part of the frame, so I doubled-up on the spacers and it just cleared the front of the frame with about 1/4" everywhere else. I didn't feel comfortable with using "So Much" spacer, so I bought 15x8's with a 3.5" backspace and kept the Mickey Thompson ET Streets. I now have anywhere from 1/2 -3/4" clearance all around. I hear 4" backspace is optimal, but not many wheels come in that backspace. If you run a smaller tire, the may fit, but if you want serious rubber out back you should go with a 3.5 or 4"bs and you'll have peace of mind. Good Luck.