Mack Defense will highlight 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, at the Walter E. Washington Convention Center in Washington, D.C.

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.

“Our team used its experience in designing and integrating advanced vehicle technologies to build these next-generation trucks,” said David Hartzell, president of Mack Defense. “These upgrades will help provide the Army with safe, innovative, cost-effective, fuel-efficient, and next-generation tactical vehicles.”

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 a material-handling crane, a wrecker/recovery truck, and a tanker truck as part of the CTT program.

The line-haul CTT hybrid tractor, the on-road tractor variant designed to replace platforms such as the M915 Line Haul Tractor, is optimized for efficient long-haul transport of heavy loads across highways and secondary roads while retaining the durability and commonality needed for the broader CTT family. Built on the proven Mack 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 Mack Defense CTT prototypes, including the line haul tractor, 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 and applied to the line-haul tractor include:

• Enhanced powertrains and idle-free systems that lower energy consumption.
• Drive-by-wire architecture supporting advanced driver-assistance systems (ADAS) such as collision avoidance, blind-spot detection, driver alerts, ABS, traction control, and vehicle dynamic controls for rollover mitigation, while also enabling future autonomous operations.
• A new suspension design that improves mobility and speed over rough terrain when needed, without compromising on-road efficiency.
• Predictive maintenance technology that increases uptime, reduces unplanned stops, and enhances 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 No. 7501 during AUSA 2026 will be:

• Prevost H3-45 motorcoach, equipped with 56 luxury passenger seats and powered by the Volvo D13 engine. The H3-45 combines advanced engineering, enhanced driver experience, exceptional passenger comfort, and the quality, reliability, and durability that have defined the Prevost brand for more than a century.
• A Volvo Construction Equipment L120, a standard commercial wheel loader adapted with key defense features. The machine is enhanced with a fording kit for water depths of up to 1.5 meters, a split cab for reduced transport height, lifting and tie-down points for air freight, defense attachment solutions, and other options designed for military use.
• The Volvo Penta D16, a proven 16.1-liter, in-line six-cylinder off-road diesel engine engineered for demanding industrial applications where high power, durability and uptime are critical. The engine combines electronic high-pressure fuel injection, an overhead camshaft, and turbocharging to deliver strong low-end torque, responsive performance, and optimized fuel efficiency. Its compact design supports straightforward installation, while accessible service points simplify maintenance and integration. The D16 provides reliable, fuel-efficient operation and dependable performance across a broad range of off-road equipment and industrial applications.