I would like to incorporate the spare tire into the rotation scheme. Where should it be placed, and what tire should be put in place of the spare? I did a rotation at 6,500, just doing the 4 (rears to front, fronts criss/crossed to the back). I figure I can squeeze a few more miles if I start doing a 5 tire rotation. Seems like a waste to leave that full size spare under the truck and never use it. I now have 12k and am ready to rotate again.