Gaseous and particle emission factors from the selected on-road petrol/gasoline, diesel, and liquefied petroleum gas vehicles

Motor vehicle emissions have been identified as the major source of air pollution in most urban cities. They have a serious impact on our urban air quality and public health. In the present study, the vehicle exhaust gaseous and particle emissions from different fuel types of on-road representative vehicles including petrol/gasoline, diesel, and liquefied petroleum gas vehicles for urban driving conditions ranging from 10 to 70 km h-1were investigated using the chassis dynamometer and remote sensing testing systems. Both testing systems have been widely used for dirty screening/clean screening credit utility programs, and for inspection and maintenance programs. T'he measured vehicle exhaust emission concentrations from both testing systems were further calculated into the average gaseous and particle (i.e., PM0.1, PM2.5, and PM10) emission factors (EFs) in milligrams or grams per kilometer for different urban driving conditions. The results show that the different fuel types of the selected on-road vehicles and their driving conditions have a direct effect on the characterization of vehicle exhaust gaseous and particle emission factors. The correlation equations of the calculated average vehicle emission factors of different size fractionated exhaust particles and hydrocarbons (HCs) in milligrams or grams per kilometer with a good regression coefficient, R2, value from different fuel types of on-road representative vehicles were also established. It is demonstrated clearly that the correlation between EFPMand EFHCis highly sensitive to the different fuel types, engine cylinder sizes and rated powers, and aftertreatment emission control and maintenance conditions of the selected on-road vehicles. The results of the present study can be used for predicting the gaseous and particle pollutants dispersion from on-road vehicles in urban roadway environments.