Vehicle Technologies Office research focuses much of its effort on improving vehicle fuel economy while meeting increasingly stringent emissions standards. Achieving these goals requires a comprehensive understanding of relationships in hybrid propulsion systems between fuel economy and emissions and control strategy, in order to minimize the fuel economy penalty associated with emissions control.

Propulsion systems research funded by the program falls into three categories:

  • Light hybrid propulsion systems, such as those used in automobiles, light trucks, and sport-utility vehicles.
  • Heavy-duty hybrid systems, such as those used in medium- and heavy-duty trucks.
  • Light vehicle ancillary systems, such as passenger cabin climate control systems, that place heavy loads on a vehicle's power source, hindering performance, fuel economy, and emissions.