Mack mDRIVE 12AO

The Mack mDRIVE® 12AO is a 12-speed automated manual transmission (AMT) engineered to deliver smooth shifting, fuel efficiency, and durability for highway and regional haul applications. The “AO” designation identifies this unit as an overdrive model, optimized for improved fuel economy at cruising speeds while maintaining the torque handling required for heavy-duty trucking.

Built exclusively for integration with Mack MP® engines, the mDRIVE 12AO uses advanced electronic controls and clutch automation to reduce driver fatigue and ensure consistent performance in demanding fleet operations. Its lightweight aluminum housing and robust internal gearing provide a balance of strength and efficiency, making it one of the most popular AMTs in the Mack lineup.

Key Features

• Automated Manual Transmission (AMT) for improved fuel economy and reduced driver fatigue
• 12 forward speeds plus multiple reverse ratios for versatile operation
• Overdrive gearing for lower engine RPM at highway speeds, reducing fuel consumption and noise
• Automated two-pedal design – no clutch pedal, reducing driver fatigue and training time
• Integrated with Mack MP® engines for predictive shifting, smooth acceleration, and grade-aware performance
• Selectable drive modes (Economy, Performance, Manual) to suit load and terrain conditions
• Lightweight, cast-aluminum housing improves payload capacity
• PTO options available for vocational applications

Technical Specifications

• Type: Automated Manual Transmission (AMT)
• Speeds: 12 forward, 2 reverse (configurable)
• Shift Control: Electronic, dash-mounted selector
• Torque Capacity: Up to 1,920–1,950 lb-ft (application dependent)
• Input Power Compatibility: Mack MP7, MP8, MP8HE, MP13 engines
• Approx. Weight: ~727 lbs (varies with configuration)
• Lubrication: Synthetic transmission fluid; extended drain intervals under standard duty