Effect of payload on exhaust emissions from light heavy-duty diesel and gasoline trucks

This paper presents the results of a study of the effects of increasing pay loads on emissions from light heavy-duty pickup trucks. Since vehicles in t his category are often more heavily loaded than passenger cars, it is impor tant to evaluate the potential impact of these additional loads on emission s. For this program, light heavy-duty vehicles we re tested over a combinat ion of th ree test weights (empty, half-loaded, and fully loaded) and diffe rent driving cycles (FTP, ST01, and CD arterial level of service cycle). Th e test matrix included five light heavy-duty diesel trucks and two light he avy-duty gasoline trucks. The diesel vehicles showed a trend of increasing PM, and CO2 emissions over the cycles used with NOx emissions increasing mo destly. The trends for the diesel THC and CO emissions were less consistent and depended on the specific cycle and vehicle. For gasoline vehicles, CO and CO2 emissions increased with increasing payload over most of the vehicl e/cycle combinations tested.