Gasoline direct injection (GDI) vehicles have been introduced by a number of auto manufacturers due to their improved fuel efficiency and reduced carbon dioxide emissions in comparison with traditional port fuel injection vehicles (PFI). GDI engines are considered as one of the technology paths for meeting emission regulations that address greenhouse gases. However, recent studies have shown that GDI engines have higher particle emissions compared with PFI engines or light-duty diesel engines equipped with diesel particulate filters. As a result, in order to meet future more stringent particulate matter emissions standards, GDI vehicles would require additional control devices, such as a gasoline particulate filter (GPF) to reduce soot and nanoparticles.

Supported by the Program of Energy Research and Development (PERD), Particle and Related Emissions Program, and the Manufacturers of Emissions Controls Association (MECA), gaseous and particulate emission measurements were conducted on a 2011 GDI-equipped vehicle and a similar PFI vehicle. Additional emission tests were then conducted on the GDI vehicle with the prototype GPF installed. The testing included characterizing the gaseous and particulate emissions under a wide range of operating conditions, including various low- and mid-level ethanol-gasoline blends, as well as temperatures from 25 to -18ºC.

Levels of particulate emissions from the ethanol-gasoline operated GDI vehicles depended heavily on the driving conditions and ambient temperature. However, the GPF effectively removed particulate emissions and successfully removed potentially harmful nanoparticle emissions. Results and experience acquired from this program provide valuable information toward the impact of test procedures on evaluating GDI vehicles and potential emission control systems, as well as insight toward technological means of reducing particulate matter emissions from future GDI vehicles.

Contact: Eric Meloche, 613-998-9590, ext 280, Emissions Research and Measurement