Abstract:Upgrading fuel quality to lower vehicle emission is vital to improve air quality in China. We conducted tunnel tests to evaluate emission of air pollutants from on-road vehicles, collected gasoline and diesel oil samples from gas station in China's eight large cities and analyzed their quality index including sulfur contents and composition of hydrocarbons, studied primarily emitted and secondarily formed aerosols from vehicle exhausts by smog chamber simulation, and further explored the relationship between fuel quality and vehicle's overall contribution to PM_2.5. Based on the analysis of the technical requirements of desulfurization, reforming and hydrogenation for upgrading fuel quality, the costs of upgrading gasoline and diesel oil quality in China was preliminarily estimated. The technological breakthrough in diesel engine manufacturing and diesel oil deep-processing is also of great importance in cutting China's vehicle emission.