Real-road NOx Emission and Fuel Consumption Characteristics of China IV Public Transit Buses

Abstract In this paper, the annual data of 50 China Ⅳ public transit buses fueled with diesel in five cities have been analyzed, and the effects of vehicle speed and acceleration on real-road NOx emission and fuel consumption characteristics have been discussed. Results showed that the annual percentage of low speed range (0-30.0 km/h) was over 70%, the acceleration range of -0.5-0.5 m/s 2 accounted for nearly 75%, and distribution of each month remained roughly stable. The highest NOx emission was concentrated in region with low vehicle speed (10.0-30.0 km/h) and high acceleration (1.0-2.0 m/s 2 ), and the highest fuel consumption was concentrated in region with high vehicle speed (40.0-50.0 km/h) and high acceleration (1.0-2.0 m/s 2 ). Both the NOx emission and fuel consumption characteristics deteriorated in summer and winter, which was mainly attributed to the using of air conditioning.