Abstract
In 2007 and 2008, the Oak Ridge National Laboratory, in collaboration with several industry
partners, collected real-world performance and situational data for long-haul operations of Class-
8 trucks from a fleet engaged in normal freight operations. Such data and information is useful
to support Class-8 modeling of heavy-truck performance, technology evaluation efforts for
energy efficiency, and to provide a means of accounting for real-world driving performance
within heavy-truck research and analyses.
This paper presents some general statistics, including distribution of idling times during
long-haul trucking operations. However, the main focus is on the analysis of some of the
extensive real-world information collected in this project, specifically on the assessment of the
effect that different types of tires (i.e., dual tires vs. new generation single wide-based tires or
NGSWBTs) have on the fuel efficiency of Class-8 trucks. The tire effect is also evaluated as a
function of the vehicle load level. In all cases analyzed, the statistical tests performed strongly
suggest that fuel efficiencies achieved when using all NGSWBTs or combinations of duals and
NGSWBTs are higher than in the case of a truck equipped with all dual tires.