Quantitative of Real-Driving Emission Factor Based on Vehicle Specific Power from A Selected Diesel Truck in Malaysia

Recent studies had highlighted that real-driving emission (RDE) testing on diesel trucks are necessary to generate emissions limits. Therefore, current research aims to conduct RDE testing using a Euro IV-compliant diesel truck on pre-designed Malaysian-based test routes. Vehicle specific power (VSP) approach was applied to examine the relationship between RDE and truck's activities. The emission factors (EFs) were divided into 22 different operating mode bins, which were classified according to the calculated VSP and instantaneous vehicle speed. Emission factors of CO, CO2, HC and particulate matter (specifically PM2.5) which quantified under time-specific EFs and distance-based EFs were the main focus in current study. Findings showed that CO2 and PM2.5 were found to react linearly with the VSP and instantaneous vehicle speed, while CO and HC emissions did not exhibit any consistent pattern. Further analysis under specific driving modes indicated that the overall EFs of CO2 and PM2.5 were found to be higher in cruising mode, while the overall EFs of CO and HC were found to be higher in acceleration mode. These findings highlighted the needs of RDE testing in providing accurate quantification of EFs under real-driving condition.