New Red 2026 Mack MD6: Cummins ISB6.7 Engine with 300 horse power. (300 HP @ 2600RPM (GOV) 660 LB-FT US21). 6 speed automatic, Allison 2500 RDS transmission (Rugged Duty Series Gen 6 with PTO provisions). Front axle 10,000 and rear axle 17,000. Wheelbase of 274 with a rear ratio of 5.57. Single axle with Spring Leaf rear suspension. (Meritor MS-17-13X W/O DIFF LOCK Casing 9.5 MM).