Penn state futuretruck hybrid electric vehicle: Light-duty diesel exhaust emission control system to meet ULEV emissions standard

Two of the goals of the Penn State FutureTruck project were to reduce the emissions of the hybrid electric Ford Explorer to ULEV or lower, and improve the fuel economy by 25% over the stock vehicle. The hybrid electric vehicle system is powered with a 103kW 2.5L Detroit Diesel engine which operates with a fuel blend consisting of ultra-low-sulfur diesel and biodiesel (35%). Lower emissions are inherently achieved by the use of biodiesel. Additionally, the engine was fitted with a series of aftertreatment devices in an effort to achieve the low emissions standards. Vehicle testing has shown a gasoline-equivalent fuel economy improvement of approximately 22%, a reduction in greenhouse gas emissions by approximately 38%, and meeting or exceeding stock emissions numbers in all other categories through the use of an advanced catalyst and control strategy. This paper will review the engine and emissions system strategy to meet the low emissions standards, detail the operation of the aftertreatment system, detail the process by which it was tested in an engine dyno lab and chassis dyno lab, and review the control optimization. Most importantly, the data will suggest what further optimization would need to be completed to meet lower emissions standards. Finally, this paper suggests some further research and questions to be answered in preparing and optimizing an aftertreatment system for a light-duty diesel engine. Figure 1The Penn State University Hybrid-Electric Ford Explorer, the "Wattmuncher". [1]