Inside the Freightliner SuperTruck 2's powertrain efficiency

A 12% increase in freight efficiency netted the Freightliner SuperTruck 2 an average 12 MPG during testing routes, said Derek Rotz, director, advanced engineering, Daimler Truck North America (DTNA), noting that the average is impacted by a host of factors including weather, load and terrain. So how did they do it?
It was a holistic effort with powertrain technologies and aerodynamics working hand-in-hand. The aerodynamics are apparent, but what's under the hood, and how did the DTNA engineering team squeeze out even more efficiency from the Detroit DD13 engine? For the answer, I talked with Jeff Murawa, manager, powertrain advanced technology and vehicle performance, DTNA, and Darek Villeneuve, advanced vehicle systems manager, DTNA, who detailed the engine component refinements, transmission technology and 48-volt electrical system architecture that made the fuel efficiency gains possible.