Technical Goals

Fuel efficiency in heavy trucks depends on a number of factors associated with the truck and its components. The top figure shows the power use inventory for a basic Class 8 tractor-trailer combination, listing its balance of fuel input, engine output, and tractive power (losses from aerodynamics, rolling resistance, and inertia). The power use inventory in this diagram highlights areas in which research efforts can lead to major benefits in truck fuel efficiency, including engine efficiency, aerodynamics, and rolling resistance.

Based on this power use inventory, the Partnership has defined specific technology goals in six critical areas that will reduce fuel usage and emissions while increasing heavy vehicle safety. The 21st Century Truck Partnership aims to support research, development and demonstration that enable achieving these goals with commercially viable products and systems. If the Partnership meets these goals, a future power use inventory for the same Class 8 tractor-trailer combination could resemble the one in the lower image instead. In this version, the new truck efficiency technologies have enabled a significant improvement in freight specific fuel consumption (ton miles per gallon).

The Partnership's Roadmap and Technical White Papers describe these specific technology goals, along with broad justification for these goals and background information on these technical areas.

Technical Teams

Several multidisciplinary teams of technical experts representing industry, academia, government, and America's national laboratories are collaborating to advance research on state-of-the-art critical medium-duty and heavy-duty truck technologies. Each team is organized around a key 21st Century Truck technology area, with a set of specific technology goals:

  • Engine Systems (engine, fuel, and emissions equipment)
  • Heavy-Duty Hybrids (electric or hydraulic hybrid drive system and energy storage)
  • Power Demands (aerodynamic drag, tire rolling resistance, drivetrain losses, auxiliary loads)
  • Idle Reduction (reduce overnight and work-day idling)
  • Safety (crash avoidance, intelligent transportation systems)
  • Operational Efficiency (vehicle duty cycle, application, driver impacts)

<p><a href="sites/prod/files/base_tractor-trailer_96.jpg" target="_self">[[{"type":"media","view_mode":"media_large","fid":"781931","attributes":{"alt":"Graphic illustration of tractor-trailer truck with red cab. Text: 21st Century Truck Partnership Technology Goals – Average payload: 11,800 kb (26,000 lbs.) – Total Mass: 25,220 kg (55,600 lbs.) – Freight Specific Fuel Consumption = 9.0 gallons/1000 ton-miles 9.4 mpg. Key Enhancements: Engine efficiency, aerodynamic improvements, low rolling resistance tires, regenerative braking (HEV). Average Power Use Inventory (Line Haul) - Fuel Input (211 kW): Engine Losses 105 kW (ƞeng=0.50), Auxiliary Power Unit 0.8 kW – Engine Output (105 kW): Accessory Loads 8 kW, Drivetrain Losses 5 kW – Tractive Power (92 kW): Aerodynamic Losses 53 kW (CD-0.52), Rolling Resistance 32 kW (CRR=0.0055), Inertia/Braking Losses 7 kW (60% regeneration efficiency).","class":"media-image caption","height":"219","style":"width: 350px; height: 219px;","typeof":"foaf:Image","width":"350"}}]]</a><br /><a href="sites/prod/files/tech_goals_96.jpg" target="_parent">[[{"type":"media","view_mode":"media_large","fid":"781936","attributes":{"alt":"Graphic illustration of tractor-trailer truck with red cab. Text: 21st Century Truck Partnership Technology Goals – Average payload: 11,800 kb (26,000 lbs.) – Total Mass: 25,220 kg (55,600 lbs.) – Freight Specific Fuel Consumption = 9.0 gallons/1000 ton-miles 9.4 mpg. Key Enhancements: Engine efficiency, aerodynamic improvements, low rolling resistance tires, regenerative braking (HEV). Average Power Use Inventory (Line Haul) - Fuel Input (211 kW): Engine Losses 105 kW (ƞeng=0.50), Auxiliary Power Unit 0.8 kW – Engine Output (105 kW): Accessory Loads 8 kW, Drivetrain Losses 5 kW – Tractive Power (92 kW): Aerodynamic Losses 53 kW (CD-0.52), Rolling Resistance 32 kW (CRR=0.0055), Inertia/Braking Losses 7 kW (60% regeneration efficiency).","class":"media-image caption","height":"219","style":"width: 350px; height: 219px;","typeof":"foaf:Image","width":"350"}}]]</a><br />For larger view, click on image.</p>