Machine description: TRI AXLE DAY CAB TRUCK TRACTOR, CUMMINS ISX15 550 HP, ENGINE BRAKE, EATON FULLER 18 SPEED, DIFF LOCK, AIR RIDE SUSPENSION, 288 IN. WB, 20K FRONTS, 46K REARS, 3RD AXLE CAPACITY 18K, DOUBLE FRAME, AIR S... more info about the 2015 Western Star 4900SB HEAVY HAUL.