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Gaseous and particle emissions from a gasoline direct injection (GDI) and a port fuel injection (PFI) vehicle were measured at various ambient temperatures (22°C, -7°C, -18°C). These vehicles were driven over the U.S. Federal Test Procedure 75 (FTP-75) and US06 Supplemental Federal Test Procedure (US06) on Tier 2 certification gasoline (E0) and 10% by volume ethanol (E10). Emissions were analyzed to determine the impact of ambient temperature on exhaust emissions over different driving conditions. Measurements on the GDI vehicle with a gasoline particulate filter (GPF) installed were also made to evaluate the GPF particle filtration efficiency at cold ambient temperatures. The GDI vehicle was found to have better fuel economy than the PFI vehicle at all test conditions. Reduction in ambient temperature increased the fuel consumption for both vehicles, with a much larger impact on the cold-start FTP-75 drive cycle observed than for the hot-start US06 drive cycle.

Selective catalytic reduction (SCR) technology is being considered as the potential strategy for significant reduction of NOx emissions from diesel engines. Many challenges exist in the development of an On-Road SCR retrofit system in terms of system integration and optimization of control strategy in order to achieve highest NOx reduction given the diversity of duty cycles. The main considered challenges are: - The development of a generic control strategy that would work for a broad range of engines, - Development of a reliable and durable injection system that would be able to withstand the harsh environments on a heavy-duty vehicle, - Packaging of the system to be able to fit on a number of vehicles with different configurations, - Controlling ammonia slip and assurance of reducing agent (Urea) availability and quality. In this study a prototype SCR system was evaluated over engine and chassis dynamometer test cycles.

Particulate emission from diesel engines is one of the most important pollutants in urban areas. As a result, particulate emission control from urban bus diesel engines using particle filter technology is being evaluated at several locations in the US. A project entitled “Clean Diesel Demonstration Program” has been initiated by NY City Transit under the supervision of NY State DEC and with active participation from several industrial partners. Under this program, several NY City transit buses with DDC Series 50 engines have been equipped with continuously regenerating diesel particulate filter system and are operating with ultra low sulfur diesel (< 30 ppm S) in transit service in Manhattan since February 2000. These buses are being evaluated over a 8-9 month period for operations, maintainability and durability of the particulate filter.

In urban areas, particulate emission from diesel engines is one of the pollutants of most concern. As a result, particulate emission control from urban bus diesel engines using particle filter technology is being evaluated at several locations in the US. A project entitled, “Clean Diesel Vehicle Air Quality Project” has been initiated by NY City Transit under the supervision of NYSDEC and with active participation from several industry partners. Under this program, 25 NY City transit buses with DDC Series 50 engines have been equipped with continuously regenerating diesel particulate filter systems and have been operating with ultra low sulfur diesel (< 30 ppm S) in transit service in Manhattan since February 2000. These buses were evaluated over a 9 month period for operations, maintainability and durability of the particulate filter.

A 1.9L turbocharged direct-injection engine representing a model year 1998-2003 Volkswagen vehicle, equipped with the OEM diesel oxidation catalyst (DOC) and exhaust gas recirculation (EGR), was tested on an eddy-current engine dynamometer with a critical flow venturi-constant volume sampling system (CFV-CVS). The engine was operated over three steady-state modes: 1600 rev/min at 54 Nm; 1800 rev/min at 81 Nm; and 2000 rev/min at 98 Nm. Commercially available ultra-low sulfur diesel fuel (≺15 ppm S) was splash-blended with fatty acid methyl ester biodiesels derived from three different feedstocks: canola, soy, and tallow/waste fry oil. Test blend levels included: 0%, 2%, 5%, 20%, 50%, and 100% biodiesel for each feedstock.

The New York City Metropolitan Transit Authority (MTA) has initiated a program to utilize various diesel emission control, alternative fuel, and hybrid electric drive technologies as part of its ongoing effort to provide environmentally friendly bus service. The New York State Department of Environmental Conservation (DEC) has joined with the MTA and Environment Canada in evaluating this program, and has established a protocol for measuring both regulated and unregulated emissions, as well as other operational parameters. This paper compares and contrasts the emissions of buses powered by Detroit Diesel Series 50 diesel engines and Series 50G Compressed Natural Gas (CNG) engines. All buses have been tested for regulated emissions at the Emissions Research and Measurement Division of Environment Canada, in Ottawa, Ontario. Unregulated emissions measurements, including particle size distributions and chemical analysis, have been supported by DEC staff.

The focus of this study was the characterization and comparison of power-specific exhaust emission rates from a closed-loop small spark-ignited engine fuelled with ethanol and isobutanol gasoline blends. A 4-cycle Kohler ECH-630 engine certified to the Phase 3 emissions standards was operated over the G2 test cycle, a six-mode steady-state test cycle, in its original configuration. This engine was equipped with electronic ignition, electronic fuel injection and an oxygen sensor. Certification gasoline fuel was splash-blended by percent volume with ethanol and isobutanol to result in the test blend levels of E10, E15, iB16 and iB8-E10. Reductions in emission rates of carbon monoxide (up to 12.0% with the ethanol blends and up to 11.4% with the isobutanol blends) were achieved along with a reduction in total hydrocarbons (up to 10.9% with the ethanol blends and up to 8.2% with the isobutanol blends). Nitrogen oxide emissions were decreased by up to 9.8% with the ethanol blends.