I'm about to put on new tires. Tire dates are 4219, Carlisle's. Spare is in a custom hanger under the trailer and never been on the ground. 2 tires are worn, 2 have 5/32". Is it acceptable to rotate the spare to the ground, install three new Carlisle's same size. I've worn out these current tires in the past 2 years, (15,000 miles) so only expect 2 years use on any new tires. Return one of the 5/32" to spare. Your advise. PM you to avoid some of the chatter in the open forum.