Truck and engine manufacturers report significant efficiency gains as a result of the public-private “SuperTruck” program.

An interim assessment of the Energy Department’s collaborative effort says that the concept vehicles are closing in on a 50% improvement in freight efficiency and a 20% improvement in engine efficiency.

“These SuperTruck program findings imply a dramatic increase in on-road freight efficiency,” said the International Council on Clean Transportation.

“The program’s results, for example, are equivalent to increasing tractor-trailer fuel economy from approximately 6 to 7 miles per gallon to approximately 9.5 to 10.5 mpg for a loaded tractor-trailer.”

In the $284 million program, DOE works with Cummins, Daimler, Navistar and Volvo to accelerate development of advanced engines, transmissions and aerodynamics, as well as other technologies.

The goal is to get the 50% efficiency improvement over a 2010 baseline by 2015, and then to make the technologies commercial by 2020.

Cummins and Daimler have already met the freight efficiency goal and Cummins has achieved more than a 20% engine efficiency gain, ICCT said.

The program has helped vet technologies such as waste-heat recovery systems, new transmissions and ultra-aerodynamic tractor-trailers, the authors said.