Thermal management is a cross-cutting technology that directly or indirectly affects engine performance, fuel economy, safety and reliability, aerodynamics, driver/passenger comfort, materials selection, emissions, maintenance, and component life. This review paper provides an assessment of thermal management for large on-highway trucks, particularly as it impacts these features. Observations based on a review of the state of the art for thermal management for over-the-road trucks are highlighted and commented on. Trends in the large truck industry, pertinent engine/truck design and performance objectives, and the implications of these relative to thermal management are presented. Finally, new thermal management concepts for high-efficiency vehicles are described.