Cummins SuperTruck Yields 54 Percent Increase in Fuel Economy

March 14, 2012


Cummins and Peterbilt Motors Company, a division of PACCAR, released test results today showing their Supertruck demonstration tractor-trailer achieved a 54 percent increase in fuel economy, averaging 9.9 miles per gallon (mpg) during testing last fall on U.S. Route 287 between Fort Worth and Vernon, Texas. The testing was conducted with a Class 8 Peterbilt 587 powered by a Cummins ISX15 engine over 11 runs meeting SAE International test standards along a 312-mile route. The tractor-trailer had a combined gross weight of 65,000 lbs.  Today's long-haul trucks typically achieve between 5.5 and 6.5 mpg. The 54 percent increase in fuel economy would save about $25,000 annually based on today's diesel fuel prices for a long-haul truck traveling 120,000 miles per year. It would also translate into a 35 percent reduction in annual greenhouse gases per truck.

The "SuperTruck" developed by the two companies features a higher-efficiency engine and an aerodynamic tractor-trailer that significantly reduces drag. The truck also includes a system that converts exhaust heat into power delivered to the crankshaft, electronic controls that use route information to optimize fuel use, tires with lower rolling resistance and lighter-weight material throughout.

In addition to the fuel economy improvements, the truck also demonstrated a 61 percent improvement in freight efficiency during testing compared to a baseline truck driving the same route. The Supertruck program has a goal of 50 percent increase in freight efficiency.

Cummins personnel have been focused on the engine and its integration with the powertrain. They have been working with several other companies and research institutions to develop numerous changes in the combustion system as well as advances to reduce internal friction and so-called "parasitic power" - excess power the engine needs to run such things as lube and coolant pumps and air compressors.

In addition to the truck's exterior, Peterbilt and its partners have been working on improvements in the drivetrain, the idle management system, weight reduction and vehicle climate control. Eaton's advanced transmission facilitates further engine downspeeding for additional fuel economy benefits. "Aerodynamics has been a significant contributor to the efficiency gains," said Scott Newhouse, Senior Assistant Chief Engineer of Product Development at Peterbilt.

Testing will continue in 2013 on a new Peterbilt 579. The testing will address use of the tractor-trailer over a 24-hour period; including periods when drivers are at rest but still need power for such things as air conditioning and small appliances.