LOUISVILLE, KY—Daimler Trucks North America’s (DTNA) SuperTruck program has achieved 115 percent freight efficiency improvement, surpassing the Department of Energy (DOE) program’s goal of 50 percent improvement.

“It is our expectation that we will continue to review and refine what we’ve learned and achieved over the course of the SuperTruck initiative, and use that knowledge to bolster our leadership in fuel efficiency,” said Derek Rotz, principal investigator for SuperTruck, Daimler Trucks North America.

The SuperTruck program is a five-year research and development initiative sponsored by the DOE, that aims to improve freight efficiency by at least 50 percent, brake thermal efficiency by 50 percent, and reduce fuel consumption and greenhouse gas emissions of Class 8 trucks.

DTNA and three other major truck OEMs were awarded multi-million dollar grants by the DOE and each matched the DOE funding dollar for dollar.

DTNA began work on the SuperTruck program in 2010 together with Detroit and other partners, including national labs, universities and suppliers and unveiled its SuperTruck at the 2015 Mid-America Trucking Show (MATS) in the Freightliner Trucks booth (#30125).

Here’s how DTNA engineers tested to measure freight efficiency: first they ran vehicle testing on highway routes in Oregon and Texas, one city route in Portland, Ore., and anti-idle testing in both a cold chamber and hot chamber. These tests resulted in a combined 115 percent freight efficiency improvement over a 2009 baseline truck.

Testing was also conducted at the DTNA Detroit engineering facility to demonstrate engine efficiency by achieving 50.2 percent engine brake thermal efficiency.

The final SuperTruck demonstrator ran a five-day, 312-mile round trip route on Texas Interstate 35 between San Antonio and Dallas, at a weight of 65,000 lbs GVWR at a speed of 65 mph, where it achieved an average result of 12.2 mpg.

Solutions of Tomorrow Today

Several commercially viable technologies developed in conjunction with the SuperTruck program have been introduced in DTNA production vehicles, including 6×2 optimization and the aerodynamic components found on the Freightliner Cascadia Evolution and the integrated DetroitPowertrain.

“By incorporating a mix of available technologies with future innovations, we were able to use the SuperTruck program to take the first steps in seeing what may be technically possible and commercially viable,” Rotz said. “We still have a long road ahead to determine ultimately what will be successful and what will achieve the greatest efficiencies.”

Downspeeding with a custom engine rating and using the predictive capabilities of Intelligent Powertrain Management (IPM) components such as pre-loaded 3D digital maps to control shifting and eCoast events also increased efficiency and economy, according to DTNA.

“We took a clean-sheet approach and looked beyond just the vehicle and engine,” Rotz said. “We examined and analyzed and tested every single angle on the truck and trailer in our quest to achieve the best results.”

Features such as energy-efficient, wide-based, low-rolling resistance single tires and highly engineered aerodynamic surfaces on the trailer also maximized efficiency.

Future Innovations

During the development of the SuperTruck, DTNA engineers investigated how high-risk, high-reward technologies used in other industries could be applied to Class 8 vehicles.

Electrified auxiliaries, controlled power steering and air systems, active aerodynamics, a long-haul hybrid system, waste heat recovery and trailer solar panels were some of the items assessed.

“Part of our process included taking a deep dive into different systems to analyze not only what might be possible, but obstacles as well,” Rotz said.

The SuperTruck team discovered that some of these components may not be commercially viable in the near future, due to regulatory or economic barriers.

Added Diane Hames, general manager, marketing and strategy for Daimler Trucks North America: “The SuperTruck program is just one of many DTNA initiatives that underscore our deep commitment to developing and implementing best-in-class fuel efficiency and aerodynamic innovations that will benefit our customers and our industry for the long-term.”