title: Time Resolved Measurements of Speciated Tailpipe Emissions from Motor Vehicles: Trends with Emission Control Technology, Cold Start Effects, and Speciation.
abstract: Experiments were conducted at the California Air Resources Board Haagen-Smit Laboratory to understand changes in vehicle emissions in response to stricter emissions standards over the past 25 years. Measurements included a wide range of volatile organic compounds (VOCs) for a wide range of spark ignition gasoline vehicles meeting varying levels of emissions standards, including all certifications from Tier 0 up to Partial Zero Emission Vehicle. Standard gas chromatography (GC) and high performance liquid chromatography (HLPC) analyses were employed for drive-cycle phase emissions. A proton-transfer-reaction mass spectrometer measured time-resolved emissions for a wide range of VOCs. Cold-start emissions occur almost entirely in the first 30-60 s for newer vehicles. Cold-start emissions have compositions that are not significantly different across all vehicles tested and are markedly different from neat fuel. Hot-stabilized emissions have varying importance depending on species and may require a driving distance of 200 miles to equal the emissions from a single cold start. Average commute distances in the U.S. suggest the majority of in-use vehicles have emissions dominated by cold starts. The distribution of vehicle ages in the U.S. suggests that within several years only a few percent of vehicles will have significant driving emissions compared to cold-start emissions.
authors.affiliation: Department of Environmental Science, Policy, and Management, University of California , Berkeley , California 94720, United States.
authors.forename: Greg T
authors.initials: GT
authors.lastname: Drozd
authors.affiliation: Center for Atmospheric Particle Studies, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States.
authors.forename: Yunliang
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Center for Atmospheric Particle Studies, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States.
authors.forename: Georges
authors.initials: G
authors.lastname: Saliba
authors.affiliation: California Air Resources Board, Sacramento, California 95814, United States.
authors.forename: Bruce
authors.initials: B
authors.lastname: Frodin
authors.affiliation: California Air Resources Board, Sacramento, California 95814, United States.
authors.forename: Christine
authors.initials: C
authors.lastname: Maddox
authors.affiliation: Department of Environmental Science, Policy, and Management, University of California , Berkeley , California 94720, United States.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Weber
authors.affiliation: California Air Resources Board, Sacramento, California 95814, United States.
authors.forename: M-C Oliver
authors.initials: MO
authors.lastname: Chang
authors.affiliation: California Air Resources Board, Sacramento, California 95814, United States.
authors.forename: Hector
authors.initials: H
authors.lastname: Maldonado
authors.affiliation: California Air Resources Board, Sacramento, California 95814, United States.
authors.forename: Satya
authors.initials: S
authors.lastname: Sardar
authors.affiliation: Center for Atmospheric Particle Studies, Carnegie Mellon University , Pittsburgh, Pennsylvania 15213, United States.
authors.forename: Allen L
authors.initials: AL
authors.lastname: Robinson
authors.affiliation: Department of Environmental Science, Policy, and Management, University of California , Berkeley , California 94720, United States.
authors.forename: Allen H
authors.initials: AH
authors.lastname: Goldstein
mesh_terms: D000393:Air Pollutants; D005742:Gasoline; D018986:Motor Vehicles; D001335:Vehicle Emissions; D055549:Volatile Organic Compounds
chemical_list: D000393:Air Pollutants; D005742:Gasoline; D001335:Vehicle Emissions; D055549:Volatile Organic Compounds