What type of transmission is commonly used in heavy-duty trucks?

Heavy-duty trucks typically utilize either manual or automated manual transmissions, which is why this choice is correct. Manual transmissions are preferred in many heavy-duty applications for their durability and the driver’s ability to control power delivery, especially when hauling large loads or navigating steep grades.

Automated manual transmissions combine the benefits of manual transmissions with the convenience of automation, allowing for easier operation without the need for a clutch pedal. This makes them increasingly popular in the trucking industry as they offer advantages in fuel efficiency and reduce driver fatigue during long hauls.

The other options focus on various types of transmissions that aren't as commonly applied in the heavy-duty truck sector. Automatic transmissions, while available, are less favored compared to their manual counterparts due to potential reduced reliability under high-torque conditions. Continuous variable transmissions are more commonly seen in passenger vehicles and are not typically designed to handle the heavy loads and demands of a truck in the heavy-duty category. Therefore, the diversity of options between manual and automated manual transmissions makes this choice the most applicable for heavy-duty trucks.