PEMS-chasing experiments were conducted for twelve heavy-duty diesel vehicles (HDDTs) to evaluate the accuracy of mobile measurement results. Two data processing approaches were integrated to automate the calculations of fuel consumption-based emission factors of nitrogen oxides (NOX). With a total of 245 plume chasing tests conducted, and then averaged by vehicle and road types, we found that the relative errors of vehicle-specific emission factors using an algorithm developed for this project were within approximately ± 20% of the PEMS results for all tested vehicles. Stochastic simulations suggested reasonable results could be obtained using fewer chasing tests per vehicle (e.g., 71% for freeways and 93% for local road, equivalent to two chase tests per vehicle). This study improves the understanding of the accuracy of the mobile chasing method, and provides a practical approach for real-time emission measurements for future scaled-up mobile chasing studies. This dataset is associated with the following publications: Wu, Y., H. Wang, K. Zhang, S. Zhang, R. Baldauf, P. Deshmukh, and R. Snow. Evaluating mobile monitoring of on-road emission factors by comparing concurrent PEMS measurements. SCIENCE OF THE TOTAL ENVIRONMENT. Elsevier BV, AMSTERDAM, NETHERLANDS, 736: NA, (2020). Baldauf, R., X. Zheng, Y. Wu, S. Zhang, K. Zhang, and J. Hao. Joint measurements of black carbon and particle mass for heavydutydiesel vehicles using a portable emission measurement system. ATMOSPHERIC ENVIRONMENT. Elsevier Science Ltd, New York, NY, USA, 141: 435-442, (2016).