Impact of Shortening Real Driving Emission (RDE) Test Trips on CO, NO_X, and PN₁₀ Emissions from Different Vehicles

The real driving emission (RDE) test is the test for vehicle type approval in the China VI emission standard and is one of the most important indicators for assessing the environmental performance of vehicles. To investigate the feasibility of shortening the RDE test trip, we measured emissions of CO, NO_X, and PN₁₀ (i.e., the number of particles above 10 nm in diameter) from gasoline, diesel, and hybrid electric vehicles based on portable emission measurement systems (PEMSs) and analyzed the influence of shortening test trips on pollutant emissions. The results indicated that the CO and PN₁₀ emission factors of the gasoline vehicle increased by about two times during short trips compared with standard trips, while the NO_X emission factor changed insignificantly. The diesel vehicle showed a two-fold increase in NO_X and PN₁₀ emission factors during short trips compared with standard trips, with CO emissions remaining largely unchanged. The short trips of the hybrid electric vehicle doubled CO and PN₁₀ emission factors and slightly increased NO_X emission factors compared with standard trips. The study can aid in improving RDE test efficiency, reducing RDE test cost, and controlling pollutant emissions from newly produced and in-use vehicles, which is crucial for air pollution management and sustainable development.