Abstract: Hydrocarbon emissions from motor vehicles are a significant source of urban VOCs pollution, and the quality of automotive gasoline plays a crucial role in determining the emission levels of motor vehicles. In this study, five light-duty gasoline vehicles that meet the China Ⅵemission standard were selected, and two test fuels with varying olefin contents were utilized to investigate the influence of gasoline olefin content on automobile gaseous pollutants and particulate matter. This was accomplished through the Type I normal-temperature test and the Type Ⅵ low-temperature test. The results indicate that under the WLTC conditions, reducing the olefin content of gasoline from 13.4% to 9.1% leads to a decrease in gaseous pollutants, specifically CO, THC, and NO_x emissions at normal temperature. This trend is particularly pronounced in urban road conditions, where the reductions in THC and CO emissions are more significant. Additionally, particulate matter emissions are also slightly reduced. At lower temperatures, CO and THC emissions continue to show a decreasing trend; however, there is no obvious pattern in the changes of NO_x emissions. These findings demonstrate that lowering the olefin content of gasoline can significantly reduce gaseous pollutant emissions across various ambient temperatures, especially in urban road conditions. This study provides crucial support for optimizing gasoline composition and mitigating automobile emissions.

Key words: environmental temperature, WLTC, gasoline, olefins content, gaseous pollutant, emissions, particulate