Mack Defense shows hybrid tractor prototype at AUSA

Mack Defense is highlighting its line haul hybrid tractor prototype for the U.S. Army’s Common Tactical Truck (CTT) program at the Association of the 2026 United States Army (AUSA) Annual Meeting and Exposition, Oct. 12-14, in Washington, D.C.

Mack Defense line haul hybrid tractor prototype. (Photo: Mack Defense)

Mack Defense was awarded a contract to design, build and deliver prototype vehicles. The prototypes have undergone testing and evaluation to help define final requirements for the Army’s next generation of heavy tactical trucks, supporting the planned modernization and eventual replacement of about 35,000 vehicles used for combat logistics, support and service-support missions.

The CTT program calls for a modern, scalable commercial-based platform that incorporates advanced safety technologies, enhanced cybersecurity, open systems architecture, greater fuel efficiency and commonality across variants to support long-term sustainability.

Based on the commercially available Mack Granite model, the prototype vehicles include an on-road tractor, an off-road tractor and a load-handling system truck. Mack Defense also provided designs for a cargo truck with material handling crane, a wrecker/recovery truck and a tanker truck as part of the CTT program.

The line-haul CTT hybrid tractor is optimized for efficient long-haul transport of heavy loads across highways and secondary roads. Built on the Granite commercial platform in a 6×4 configuration, it draws on the same scalable architecture as the other prototypes to maximize parts commonality, simplify sustainment and lower lifecycle costs.

All three CTT prototypes incorporate high-voltage hybrid-electric systems. These systems reduce fuel demand, enable extended anti-idle/silent-watch operation and provide exportable power – capabilities critical for contested logistics environments where refueling may be limited and soldiers increasingly rely on onboard electronics, communications and potential microgrid support.

Additional features shared across the prototypes include:

• Enhanced powertrains and idle-free systems to lower energy consumption.
• Drive-by-wire architecture supporting advanced driver-assistance systems (ADAS) while also enabling future autonomous operations.
• A new suspension design to improve mobility and speed over rough terrain when needed, without compromising on-road efficiency.
• Predictive maintenance technology to increase uptime, reduce unplanned stops and enhance driver safety.
• Advanced cybersecurity measures and open systems architecture to facilitate upgrades, including future autonomous capabilities and further electrification.
• Commercial-derived safety and operator technologies adapted for military use.

Also featured in the Mack Defense booth during AUSA 2026 is the Prevost H3-45 motorcoach, equipped with 56 luxury passenger seats and powered by the Volvo D13 engine; a Volvo Construction Equipment L120 standard commercial wheel loader adapted with key defense features; and the 16.1 L Volvo Penta D16 inline six-cylinder off-road diesel engine engineered for demanding industrial applications.