After meeting the president and hosting dignitaries at the U.S. Department of Energy (DOE), the Cummins-Peterbilt SuperTruck is finally getting a rest.

But the most significant part of its more than four-year journey could just be starting.

“We learned a tremendous amount not just about features like waste heat recovery but about the base engine itself,” said David Koeberlein, Cummins Principal Investigator for SuperTruck. “This has been an extremely valuable project.”

Done in partnership with the DOE, SuperTruck started in 2012 to spur innovation in the industry. Cummins partnered with the Peterbilt Motors Company, a division of PACCAR, to lead one of several SuperTruck teams. Their team had several objectives as part of the public-private partnership, including demonstration of a clean and highly efficient engine with an advanced waste heat recovery system and an aerodynamic tractor and trailer.

The Cummins-Peterbilt SuperTruck made headlines in February of 2014 when the companies announced it achieved 10.7 miles per gallon (mpg) under real-world driving conditions. At one time, that would have been considered impossible. Most trucks today get between about 5.5 and 6.5 mpg.

Using the industry leading Peterbilt Model 579 tractor, the Cummins- Peterbilt SuperTruck was powered by an engine based on the Company’s ISX15. It converted exhaust heat into power delivered to the crankshaft, used route information to optimize fuel use, and included many other features.

When U.S. President Barack Obama called for new fuel-efficiency standards for medium- and heavy-duty commercial vehicles in 2014, he did it in front of the SuperTruck developed by Cummins and Peterbilt.