Effect of Payload on Exhaust Emissions from Light Heavy-Duty Diesel and Gasoline Trucks

Abstract

This paper presents the results of a study of the effects of increasing payloads on emissions from light heavy-duty pickup trucks. Since vehicles in this category are often more heavily loaded than passenger cars, it is important to evaluate the potential impact of these additional loads on emissions. For this program, light heavy-duty vehicles were tested over a combination of three test weights (empty, half-loaded, and fully loaded) and different driving cycles (FTP, ST01, and CD arterial level of service cycle). The test matrix included five light heavy-duty diesel trucks and two light heavy-duty gasoline trucks. The diesel vehicles showed a trend of increasing PM, and CO2 emissions over the cycles used with NOx emissions increasing modestly. 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 vehicle/cycle combinations tested.