Class-8 Heavy Truck Duty Cycle Project Final Report - Center for ...

9. FUTURE DIRECTIONS
The Heavy Truck Duty Cycle (HTDC) Project has provided a rich source of Class-8 long-haul
performance data. This data has breadth in that it addresses a wide range of parameters that can
influence performance, and it has depth in that it provides values of particular parameters for large
ranges of the values of other parameters. In particular, the fuel efficiency of the test vehicles in terms
of the variation in payload, road grade, weather, congestion/road type, etc. Of primary benefit to the
ORNL research team has been the experience and lessons learned from the pilot test conducted in
2005 through the completion of the FOT in 2008. This strong experiential base linked with the
positive results of the HTDC project suggests future directions in the area of truck-based duty cycles
and performance data.
Although Class-8 long-haul operations is responsible for most of the fuel consumed in Class-8
applications, Class-8 short-haul applications in urban and metropolitan areas represent a significantly
different set of performance criteria. A future direction of research involves collecting, archiving and
analyzing data and information on non-long-haul Class-8 operations.
Class-6 trucks represent the second largest class of fuel consumers in heavy/medium truck spectrum.
These trucks have duty cycles that are vocationally dependent, log significantly fewer miles per
vehicle year than Class-8 trucks, and often utilize the truck’s engine as a source of power for the
operation of, for example, the arm of a bucket truck. As a result, a significant portion of the fuel
consumed is done by the Power Take-Off (PTO) functions. A future direction of research involves
collecting, archiving and analyzing data and information on Class-6 operations in selected vocations.
Hybrid technologies have been demonstrated successfully in smaller vehicles that are less than Class-
6. However, many of the truck OEMs are considering hybrid drive applications for heavy- and
medium-sized trucks. Although the stop-and-go nature of duty cycles is understood as making the
best use of hybrid technologies, and the theory of hybrid applications is well understood, real-world
applications may prove to be different. A future direction of research involves the vocational aspects
and duty cycles of the various truck classes (3 through 8) to determine the vocations and specific
applications that would benefit most from a hybrid platform. Furthermore, for these duty cycles, and
for selected vocations, a cost-benefit study will be conducted that clearly illustrates the hybrid
technology benefits to various vocations. This study would allow end-users who are considering
hybrids to determine if their operation is a good candidate for hybrid technologies and also allow
them to determine when the return-on-investment achieves pay-back. A simple “calculator” could be
developed with input such as: Vehicle Class (GVWR), Combination/Straight Truck, Total Miles
Driven, Average Weight, Total Time Idling, Power Take-Off Time, Driving Environment, etc. The
calculator could give a quantitative score (e.g., 1-to-10 or 1-to-100) as to the “fit” for a particular
application to go hybrid, and could give an estimate of annual fuel savings.
EPA’s SmartWay Program is focused on increasing the energy efficiency and reducing greenhouse
gases and air pollution for heavy and medium-sized trucks operating on our highways. SmartWay
certification of a fleet assures the public that the owners and operators of the fleet are energy
efficiency and environmentally minded. A challenge for the Program is how to certify various classes
and vocational application of heavy- and medium-sized trucks. Discussions to date have included a
reference truck configuration and representative sets of duty cycles per application/vocation which
real-world fleets can compare themselves to. What is lacking is the existence of real-world-based
duty cycles for comparison purposes, especially those involving the emissions from these vehicles
operating on these duty cycles. Dyno and test track testing offer the opportunity to collect emissions
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