INFLUENCE OF AMBIENT TEMPERATURE ON TAILPIPE EMISSIONS FROM 1984-1987 MODEL YEAR LIGHT-DUTY GASOLINE MOTOR VEHICLES

Motor vehicle emissions are sensitive to a number of variables including ambient temperature, driving schedule (speed versus time), and fuel composition. Hydrocarbon, aldehyde, carbon monoxide, and oxides of nitrogen emissions were examined with 9 recent technology 4-cylinder gasoline motor vehicles at 70F, 40F, and 20F. About 200 hydrocarbon and 12 aldehyde compounds were included in the organic emissions characterization. Two fuels and two driving schedules were used. Typically, hydrocarbon and carbon monoxide emissions were significantly increased by reduced ambient temperature. Oxides of nitrogen emissions also increased, but to a lesser extent. There were no predictable formaldehyde emissions trends with temperature. Paraffinic and aromatic hydrocarbon emission fractions were sensitive to fuel composition, but the olefinic emission fraction (dominated by ethylene and propylene) was not. With low temperature cold start tests, preceding transient driving with a 5 minute engine idle resulted in reduced carbon monoxide emission rates and elevated oxides of nitrogen emission rates. Hydrocarbon emission rates were not predictably sensitive to the preliminary idle.

• Supplemental Notes:
  • Pub. in Atmospheric Environment, v23 n2 pp307-320 1989.
• Corporate Authors:

  Environmental Protection Agency

  Atmospheric Sciences Research Laboratory
  Research Triangle P., NC  United States  27709
• Authors:
  • Stump, F
  • Tejeda, S
  • Ray, W
  • Dropkin, D
  • Black, F
• Publication Date: 1989

Media Info

• Pagination: 16 p.

Subject/Index Terms

• TRT Terms: Aldehydes; Carbon monoxide; Cold weather; Engine idling; Formaldehyde; Fuel mixtures; Gasoline engines; Hydrocarbons; Nitric oxide; Nitrogen oxides; Olefins; Paraffin; Pollutants; Sensitivity analysis; Speed; Temperature
• Uncontrolled Terms: Cylinders
• Old TRIS Terms: Emission rates; Idling
• Subject Areas: Highways; Vehicles and Equipment; I91: Vehicle Design and Safety;

Filing Info

• Accession Number: 00494006
• Record Type: Publication
• Source Agency: National Technical Information Service
• Report/Paper Numbers: EPA/600/J-89/019
• Files: TRIS
• Created Date: Apr 30 1990 12:00AM