Abstract: Real driving emission (RDE) tests are conducted by using a portable emission measurement system (PEMs) for a light duty gasoline vehicle equipped with a natural aspiration and port fuel injection (PFI) engine in accordance with China Ⅵ emission regulation of light-duty vehicles and moderate driving and dynamic driving are defined based on trip dynamics. Results show that NOx and PN emissions exhibit a small difference between dynamic driving and moderate driving, but the CO emission for dynamic driving is 84 times and 75 times of that for moderate driving in city trip and total trip respectively. Frequent acceleration and deceleration of dynamic driving is the major reason for drastic increase of CO emission. CO emission is proportional to the acceleration in the city trip. And the bad emission calibration for the high speed and high load condition may be responsible for the high CO emission in the motorway trip.

Key words: light-duty vehicle, port fuel injection, real driving emissions, moderate driving, dynamic driving