Comparative investigation of regulated emissions and nano-particle characteristics of light duty vehicles using various fuels for the FTP-75 and the NEDC mode

This study was focused on experimental comparisons of the effects of various vehicle certification modes on the nano-particle and regulated emission characteristics of light duty vehicles with gasoline, diesel particulate filter (DPF) diesel, liquefied petroleum gas (LPG) and non-DPF diesel. The particulate matter, regulated emissions, and CO₂ emission of various fueled vehicles were analyzed with the golden particle measurement system, as recommended by the particle measurement program. The solid particles with a diameter above 23 nm, which in only non-volatile, were measured using a particle number counter (CPC). The vehicle tests were performed on the federal test procedure-75 (FTP-75) and the new European driving cycle (NEDC) mode, and the results were compared to evaluate particle formation with both CPC and a differential mobility spectrometer (DMS500). Particle formation was highly dependent on the vehicle speed and load conditions of each mode. In particular, the particle numbers of conventional fuels sharply increased during cold start, fast transient acceleration, and high-load operation phases of the vehicle emission tests. The DPF diesel vehicle fitted with a particulate filter showed substantial reduction of particulate matter whose number concentration was equivalent to those of gasoline and LPG fueled vehicles. It was found that particle emission and regulated emissions as well as CO₂ emission, and fuel economy were closely related with vehicle driving patterns and fuel composition, simultaneously. Finally, sub-23 nm nucleation mode particles using DMS500 were majority in the gasoline and LPG vehicles, whereas accumulation mode particles were mainly discharged in the diesel vehicles.