The Department of Energy is backing development of clean-burning, more fuel-efficient vehicles with cold cash, including $115 million for the Super Truck program. Announced earlier this year, the program is awarding grants to three teams, headed by Daimler Trucks North America, Navistar International and Cummins.

Each will invest matching sums to develop high-tech demonstration vehicles that will attempt to lower emissions of greenhouse gases and improve fuel economy by half again over today's levels.

The funding is part of a larger effort to spend $187 million in nine projects to increase fuel efficiency in heavy-duty trucks and passenger vehicles.

The manufacturers say they will explore improved aerodynamics, advanced combustion techniques and waste heat recovery, powertrain hybridization, reduced engine idling and smaller engine size, among other things, to increase fuel economy. Each team will build vehicle prototypes that can efficiently move large amounts of freight. They will use an "integrated" approach that pairs tractors with trailers, particularly by designing complementary streamlining.

DTNA, which builds Freightliner and Western Star trucks, will receive about $40 million. It will work with sister company Detroit Diesel, "to undertake a broad research program toward the objectives of improving freight efficiency 50 percent over the current state-of-the-art and reaching 50 percent brake thermal efficiency," the company states in an abstract to a project summary with which it successfully applied for its grant.

Thermal efficiency of diesels is now in the mid-40-percent range, meaning more than half the energy in diesel fuel is now consumed by internal friction and wasted as heat. All engine systems, including turbocharging, cooling and accessory drives, will be improved by DDC's research, and use of a downsized engine is among the routes to explore.

Work will be done by about 40 employees in Portland, Ore., and Detroit, Mich. Partners will include Oak Ridge National Laboratory, Delphi, Oregon State University, BAE Systems, ArvinMeritor and Schneider National.

Navistar will get $37.3 million to develop and demonstrate fuel-efficient technologies, including aerodynamics, combustion efficiency, waste heat recovery, hybridization, idle reduction and reduced rolling resistance tires. It will in effect expand work already done on the company's engines and road tractors, the firm said.

Cummins will receive $54 million to work on both the Super Truck and a light-duty project. Partnering with Peterbilt and Eaton, Cummins will use $39 million to develop a clean diesel engine, an advanced waste heat recovery system, an aerodynamic Peterbilt tractor using an advanced automated mechanical transmission and a fuel cell auxiliary power unit to reduce engine idling. An aerodynamic van trailer will complement the tractor.

The DOE initiative echoes development work done by manufacturers more than a quarter century ago. Shortly after the Arab oil embargo of 1979, Navistar, Peterbilt and now-defunct Fruehauf Trailer experimented with integrated tractor-trailer combinations that achieved high-mpg figures, in two cases with vehicles that were practical enough for everyday use.

Freuhauf's futuristic FEV2000, designed by Airflow Sciences Corp., was made up of an International cabover tractor and a skirted, boat-tailed van trailer with virtually no gap between them. It achieved 7.4 mpg compared to 4.3 mpg for a baseline vehicle typical of the early '80s.

Peterbilt showed that an aerodynamic van with a belly skirts and a "truncated boat tail" alone improved the efficiency of a modified Model 372 cabover by 1.5 mpg.

Navistar advertised that an aero-improved daycab tractor with a Cummins L10 engine had delivered 8.3 mpg in a highly controlled cross-country run.

Few of the demo rigs' designs were embraced by truckers, because more stable oil supplies and cheaper fuel prices encouraged them to continue with status quo equipment. Recent world economic and geopolitical changes and increasingly expensive fuel might make lessons from Super Truck, born of an activist administration and Congress in Washington, more enduring.

From the June 2010 issue of Heavy Duty Trucking.