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Regulated and unregulated exhaust emissions from four late model 3-way catalyst passenger cars were measured over the urban dynamometer driving schedule of the Federal Test Procedure as a function of ambient temperature (50°F-81°F). Fuel economy, regulated emissions HC, CO, NOx, and unregulated emissions NH3, HCN, N2O, CH4, COS, H2S, SO2, SO4, and C6H6 were studied. It was found that reduced ambient temperature operation (<68°F) significantly increased the regulated emissions HC and CO, and slightly increased several unregulated emissions. Within the limitations of this study, none of the unregulated emissions were emitted at concentrations that could be considered hazardous to the public.

Exhaust emissions from two diesel passenger cars were measured as a function of ambient temperature (43 - 82°F) over the urban dynamometer driving schedule of the Federal Test Procedure (FTP). Low ambient temperature did not affect rates of emission of total hydrocarbons, carbon monoxide, or nitrogen oxides. Fuel economy decreased with decreasing test temperature. Total particulate matter increased with decreasing test temperature, as did particulate organic emission rates (due primarily to adsorption of uncombusted diesel fuel). Polynuclear aromatic hydrocarbon emissions (ug/mile) and mutagenicity in the Ames Salmonella bioassay (rev/mile) were not affected by decreasing test temperature.

An experimental program was conducted to characterize the gaseous and particulate emissions from a 1975 Peugeot 504D light duty diesel-powered vehicle. The vehicle was tested over the 1975 Federal Test Procedure, Highway Fuel Economy Test, and Sulfate Emissions Test driving cycles using four different fuels covering a fair range of composition, density, and sulfur content. In addition to fuel economy and regulated gaseous emission measurements of hydrocarbons, carbon monoxide, and oxides of nitrogen, emission measurements were also obtained for non-regulated pollutants including sulfur dioxide, sulfates, aldehydes, benzo[a]pyrene, carbonyl sulfide, hydrogen cyanide, nonreactive hydrocarbons, and particulate matter. The results are discussed in terms of emission trends due to either fuel type or driving cycle influence.

Gaseous and particulate emission rates from seven class 2B, one class 5 and six class 6 heavy-duty gasoline- and diesel-powered trucks were determined using transient chassis dynamometer test procedures. All vehicles were tested at approximately 70% of their rated gross vehicle weight over the Heavy-Duty Transient Cycle and the Durham Road Route driving cycles. The sensitivity of emission rates to vehicle configuration, engine design, and driving cycle characteristics was examined. Emissions characterization included total hydrocarbons, carbon monoxide, oxides of nitrogen, fuel economy, total particulate matter, CH2Cl2 %-extractables, particulate organics, inert material, particle size less than 2μ, and lead, bromine, and chlorine analyses. For a particular type of engine (gasoline or diesel), class 2B truck emission rates were less than class 5 or 6 truck emission rates.