Date of Graduation


Document Type


Degree Type



Statler College of Engineering and Mineral Resources


Mechanical and Aerospace Engineering

Committee Chair

Mridul Gautam


The objective of this study was to evaluate the performance and emissions profiles of a prototype Series Hydraulic Hybrid Diesel Vehicle (SHHDV). The test vehicle was a collaborative effort between Parker-Hannifin and Autocar. The outcome of which was an extensive set of data and a compilation of "lessons learned," which were to be applied for further development of these vehicles. Research is needed in this area for developing a better understanding of the benefits from hydraulic hybrids. The vehicle platform used in this study was that of Autocar's Xpeditor model, a diesel powered cab-over refuse truck. The hydraulic hybrid and a baseline vehicle were evaluated on the West Virginia University (WVU) Transportable Heavy-Duty Vehicle Emissions Testing Laboratory with two test cycles that were developed using in-use data provided by Parker-Hannifin and Autocar from a refuse vehicle route. The first cycle, labeled Saginaw Pick-Up (SPU), mimicked the stop-and-go driving typical of a vehicle's operation during real-world refuse collection. The second cycle, labeled Saginaw Transport Cycle (STC), mimicked the high speed transport seen during the vehicle's operation to and from the point of origin. The testing gave insight to the potential of this technology with valuable information for further refinement. The hybrid vehicle was successful in following the low speed stop-and-go test cycles; however it was unable to fully attain the designed high speed transport cycle. In the end, the hybrid test vehicle failed to achieve its primary goals of overall emissions reduction and improved fuel economy. The hybrid produced an average of 23.4% more carbon dioxide (CO 2), 11.8% lower oxides of nitrogen (NOx) and 21.9% lower fuel economy during the low speed SPU test cycles. For the high speed STC tests, the hybrid vehicle only followed the test cycle adequately during one of the tests (STC 2). During STC 2 the hybrid vehicle produced 8.27% more CO2, 5.85% lower NOx and 19.4% lower fuel economy.