Finding 8-2. Rather than have a number of targets for each subsystem, the SuperTruck projects have only two types of goals: one for the engine and one for overall vehicle fuel efficiency. This approach reflects the EPA and NHTSA approach to heavy-duty fuel efficiency regulations. Each project team is allowed to select a set of technologies that meet the project goals. The engine goal of 50 percent BTE for the demonstration vehicle appears to be feasible, although there is risk in being able to achieve it at a cruise condition. The engine goal of 55 percent BTE demonstrated in a test cell is very high risk but might be achievable. The overall vehicle goal of a 33 percent reduction in load-specific fuel consumption appears to be feasible.
Finding 8-3. Unfortunately, the SuperTruck program expresses vehicle efficiency targets in terms of fuel economy rather than fuel consumption. The vehicle target is stated as a 50 percent improvement in fuel economy rather than as a 33 percent reduction in fuel consumption. This can lead to confusion regarding the actual benefits of the program.
Recommendation 8-1. The DOE should state the SuperTruck program vehicle efficiency goals in terms of load-specific fuel consumption and track progress on this basis—that is gallons per 1,000 ton-miles, which is the metric used in the EPA/NHTSA fuel consumption regulations.
Finding 8-4. The committee believes that the SuperTruck project teams have developed plans that address the needs of the SuperTruck program and that have a reasonable chance for success. The keys to success include proper implementation of the plans along with the flexibility to adapt to new information and intermediate results during the course of the project.
Finding 8-5. The SuperTruck projects allow each team to design its own test duty cycle(s) within certain constraints. One negative consequence of this approach is that the three trucks may never be tested using a common cycle for comparison.
Recommendation 8-2. The DOE and the SuperTruck contractors should agree on at least one common vehicle duty cycle that will be used to compare the performance of all three SuperTruck vehicles. In addition, fuel consumption improvements should be calculated on the basis of the EPA and NHTSA fuel consumption regulations.
Finding 8-6. The SuperTruck projects go beyond the scope of previous 21CTP projects. Instead of relying entirely on simulations and laboratory testing, each of these projects will result in a drivable truck. The committee believes that it is important to take technologies that have been developed to date and implement them in a real vehicle. Often, the implementation of new technologies in real-world applications yields unexpected results, and these results must be explored before any new technology can be considered ready for production implementation.
ATRI (American Transportation Research Institute). 2011. Idling Regulations Compendium. Available at http://www.atri-online.org/index.php?option=com_content&view=article&id=164&Itemid=70. Accessed January 18, 2011.
DOE (U.S. Department of Energy). 2010a. Secretary Chu Announces $187 Million to Improve Vehicle Efficiency for Heavy-Duty Trucks and Passenger Vehicles. Washington, D.C. Available at http://www.energy.gov/8506.htm.
DOE. 2010b. Funding Opportunity Number: DE-FOA-0000079. U.S. Dept of Energy, Recovery Act—Systems Level Technology Development, Integration, and Demonstration for Efficient Class 8 Trucks (SuperTruck) and Advanced Technology Powertrains for Light Duty Vehicles (ATP-LD), DE-FOA-0000079. August 24. Washington, D.C.: Department of Energy. Available at http://www.energy.gov/recovery/documents/zeDE-FOA-0000079.pdf.
DOE. 2010c. Multi-Year Program Plan 2011-2015. December. Washington, D.C.: Office of Vehicle Technologies.
NRC (National Research Council). 2008. Review of the 21st Century Truck Partnership. Washington, D.C.: The National Academies Press.
NRC. 2010. Technologies and Approaches to Reducing the Fuel Consumption of Medium- and Heavy-Duty Vehicles. Washington, D.C.: The National Academies Press.