This paper examines the powertrain and braking efficiency of a wide spectrum of light duty vehicles to illustrate the range of efficiencies that exist and to isolate the contribution of hybrid and non-hybrid powertrains in reducing fuel consumption. The paper also examines the change in vehicle energy demands, e.g. aerodynamics and rolling resistance from 2005 models to 2010 models to highlight the role that vehicle energy consumption reduction plays in determining total fuel consumption. EPA fuel economy certification data is analyzed using the metrics of vehicle limited fuel consumption and powertrain and braking efficiency. From the data, conclusions are drawn to create a list of the ten most efficient powertrains, based on the powertrain and braking efficiency metric, and the ten vehicles with the lowest vehicle limited fuel consumption. These metrics provide an informative basis for current and future technology evaluations.