Tri-Drive Cab and Chassis, has a 550 HP ISX Power plant with a 18 speed transmission, 16,000lb Front and 46,000lb Rear. Neway Air Ride Suspension. 268" Wheel Base,140" back of Cab to first Drive tire,56" from first drive to second drive,56" from second drive to third drive,23' 10" from back of cab to end of frame.