The U.S. Department of Energy, through Argonne National Laboratory, and in cooperation with Natural Resources-Canada and Chrysler Canada, sponsored and organized the 1996 Propane Vehicle Challenge (PVC). For this competition, 13 university teams from North America each received a stock Chrysler minivan to be converted to dedicated propane operation while maintaining maximum production feasibility. The converted vehicles were tested for performance (driveability, cold- and hot-start, acceleration, range, and fuel economy) and exhaust emissions. Of the 13 entries for the 1996 PVC, 10 completed all of the events scheduled, including the emissions test. The schools used a variety of fuel-management, fuel-phase and engine-control strategies, but their strategies can be summarized as three main types: liquid fuel-injection, gaseous fuel-injection, and gaseous carburetor.
The converted vehicles performed similarly to the gasoline minivan. The University of Windsor's minivan had the lowest emissions, attaining ULEV levels (0.035 g/mi NMHC, 0.21 g/mi CO, 0.21 g/mi NOx) with a gaseous-injected engine. Texas A&M vehicle, which had a gaseous-fuel injection system (0.062 g/mi NMHC, 0.67 g/mi CO, 0.27 g/mi NOx) and the GMI Engineering and Management Institute's vehicle, which had a liquid-injection system (0.097 g/mi NMHC, 1.26 $/mi CO, 0.25 g/mi NOx), both reached LEV levels.
Vehicles with an injection fuel system (liquid or gaseous) performed better in terms of emissions than a carbureted systems. Liquid injection appeared to be the best option for fuel metering and control for propane, but more research and calibration are necessary to improve the reliability and performance of this design.