4" backspacing works good in the rear but I've found you really need 4.25"-4.5" in the front. At least on a Cutlass.
My 17x8's with 4" BS and 245/45 tires would rub on the chrome trim and inner fender on large bumps.
My 17x8's with 4" BS and 245/45 tires would rub on the chrome trim and inner fender on large bumps.