Search Results

Gasoline direct injection (GDI) engines have improved thermodynamic efficiency (and thus lower fuel consumption) and power output compared with port fuel injection (PFI) and their penetration is expected to rapidly grow in the near future in the U.S. market. In addition, the use of alternative fuels is expanding, with a potential increase in ethanol content beyond the current 10%. Increased emphasis has been placed on butanol due to its more favorable fuel properties, as well as new developments in production processes. This study explores the influence of mid-level ethanol and iso-butanol blends on criteria emissions, gaseous air toxics, and particulate emissions from two wall-guided gasoline direct injection passenger cars fitted with three-way catalysts. Emission measurements were conducted over the Federal Test Procedure (FTP) driving cycle on a chassis dynamometer.

This study provides one of the first evaluations of the integrated particle size distribution (IPSD) method in comparison with the current gravimetric method for measuring particulate matter (PM) emissions from light-duty vehicles. The IPSD method combines particle size distributions with size dependent particle effective density to determine mass concentrations of suspended particles. The method allows for simultaneous determination of particle mass, particle surface area, and particle number concentrations. It will provide a greater understanding of PM mass emissions at low levels, and therefore has the potential to complement the current gravimetric method at low PM emission levels. Six vehicles, including three gasoline direct injected (GDI) vehicles, two port fuel injected (PFI) vehicles, and one diesel vehicle, were tested over the Federal Test Procedure (FTP) driving cycle on a light-duty chassis dynamometer.

The introduction of biofuels is seen as a very important measure to reduce the emissions of greenhouse gases from the transport sector. Currently, ethanol is the most widely used renewable fuel for transportation in the US and with the push to use increasingly higher levels of renewable fuels, there has been an accompanying push to further increase the ethanol level in gasoline. In addition to ethanol, butanol, an alcohol which can be produced from biomass sources, has recently received more attention as an alternative to gasoline for use in spark ignition (SI) engines. For this study, two 2007 model year and one 2012 model year light-duty vehicles equipped with a three-way catalyst (TWC) were employed. For the 2007 model year vehicles, emissions and fuel economy measurements were made for E10 (reference fuel), E15, E20, and B16 fuels. The latter corresponds to a blend of gasoline and 16% of butanol, which is the equivalent of E10 in terms of oxygen content.