Excessive tire wear on the rear tires of my Tibruon have me frustrated. After 75,000 Hwy. km I have gone through 3 sets of tires. The rear wheel alignment does not keep even though my front wheels have never been out. My last set now need replacing after 12,000 kms. on even thread wear. I couldn't even rotate them to get max wear from all tires. My front tires still look new. Help someone please.