The Mack mDRIVE mDRIVE XD is a 12-speed automated manual transmission listed for on-highway applications. Recorded for mDRIVE XD: brand Mack, family Mack mDRIVE, series mDRIVE, type automated manual, speed 12-speed, application on-highway. Gear ratios, torque ratings, and interchange details are verified per unit against your tag or VIN rather than published here. Availability: Available Now.