Particulate emissions from gasoline direct injection engines: A review of how current emission regulations are being met by automobile manufacturers.

Gasoline direct injection (GDI), which is one of the fuel injection technologies extensively used in internal combustion engines, is a viable alternative for port fuel injection technology in premium gasoline (petrol)-run vehicles; furthermore, it provides a better fuel economy, higher thermal efficiency, and greater power output. However, the particulate emissions ejected from modern GDI engines are an environmental and health hazard. As a result, stringent emission legislations are imposed on the production/incorporation of GDI engines. This study reviews the particle masses (PMs) and particle numbers (PNs) of various GDI engines. The backgrounds and highlights of current and future PM emission regulations (Euro 5-6 and China 5-6 GDI engine legislations) are discussed. In addition to the effects of cold-start and oxygenated fuel on PM emissions, this paper also reviews the impacts of engine parameters. Another area of discussion is the particulate filter technology as a solution for pollution control. Concerns about PM emissions from GDI engines are conceptually similar to those about emissions from diesel engines. Finally, this paper discusses the technical and commercial aspects of the use of the particulate matter control technology of GDI engines, such as particulate gasoline filters, as dedicated GDI filtration devices.