Research on the Impact of Ambient Temperature on Heavy-Duty Diesel Vehicle NOx Emissions

The main source of nitrogen oxide (NOx) pollution has been identified as diesel-powered vehicles. The results of the analysis of remote sensing device (RSD) data from 25,853 heavy-duty diesel vehicles (HDDVs) in Chengdu show that ambient temperature has a significant impact on NOx emissions. This connection helps to explain why wintertime pollution levels tend to be higher than usual. To investigate whether the increase in NOx emissions during low temperatures is due to the vehicles themselves or the constrained dispersion of pollutants in cold weather, we analyze the NOx emission patterns of individual vehicles using on-board diagnostics (OBD) data. Our findings demonstrate low ambient temperatures have a considerable, detrimental effect on emissions. This critical dependency on temperature is often overlooked in current emission inventories, despite its profound implications for maintaining air quality standards.