I finally bought a 33x12.5r15 spare to match my set. I’m 7,500 miles into my Cooper STT Pro’s and have done one 4-point rotation at about 2,000 miles. This data will be interesting for those who have a recent set. I wanted to work a fifth tire into the rotation so I bought a new one today and had it mounted and balanced. I had them rotate and balance the others. When they measured my tread depth they were all 17/32”, so they are wearing very evenly at this point, confirming good alignment and tire pressure. I run 26psi. The tires begin with 21/32” tread, so at this rate on the roads I drive you lose 4/32 (1/8”) for every 7,500 miles. With the 5th tire in the rotation I’m calculating I can get 25,500 miles on this set. At that point I estimate I’ll be down to 7/32”. No muy bueno, but they are MT’s, so what do you expect!? Here’s a pic of the new spare on my Jeep. Not the best pic, but hey, there’s tomorrow...Jeep is almost perfectly level with this setup
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