Dad was a used car dealer, he went to local new car dealer every day to buy the 2-3 year old car trade-ins. Got a lifetime supply of tires from their dumpster, all knee deep in thread depth. Sometimes just a nail hole, other times they looked perfect (customer just complained and wanted a new set), other times just cupped up a bit. We mounted them up and drove them all till worn out, never had a problem. Still have a cellar full for rest of our lives. Got to sell off the sizes we don't use, to make some room.