Which of the following features contributes to the JLTV's mobility?

The powerful off-road engine performance is a critical feature that significantly contributes to the mobility of the Joint Light Tactical Vehicle (JLTV). This capability allows the JLTV to traverse various terrains, including rugged and uneven landscapes, which is essential for military operations. A robust engine provides not only the necessary power to accelerate and maintain speed on rough surfaces but also the torque needed to overcome obstacles and steep inclines. This strength enhances the vehicle's ability to maneuver quickly and effectively in diverse environments, fulfilling its role in providing tactical mobility for troops and equipment.

In contrast, while advanced radar systems, heavy-duty external chassis, and high-tech navigation interfaces play significant roles in overall vehicle capabilities, they do not directly impact mobility in the same way. Radar systems are primarily for detection and situational awareness, a heavy-duty chassis can contribute to durability but does not enhance mobility performance, and navigation interfaces do not influence the vehicle's physical ability to move across varied terrains. Thus, the engine's performance is fundamental for achieving the desired mobility outcomes in operational scenarios.