The US EPA released a white paper on the Tier 2 (Phase 2) Study to assess further reduction in light-duty vehicle and light-duty truck tailpipe emission standards. The study shall cosider whether to establish, for gasoline and diesel-fueled light-duty vehicles and light-duty trucks of model years 2003 and later, the following emission standards:

  • NMHC - 0.125 g/mi
  • NOx - 0.2 g/mi
  • CO - 1.7 g/mi

This paper discusses the approach EPA intends to take in conducting the air quality, technology, and cost effectiveness assessments required by the CAAA. The document is available on the Internet at the EPA Tier 2 Study home page at

A public workshop regarding Tier 2 exhaust emission standards will be held on 23 April 1997, at the US EPA Judiciary Square Office, 1st Floor Conference Room, 501 3rd Street NW, Washington, DC.

For further information contact: Jim Markey, Vehicle Programs and Compliance Division, US Environmental Protection Agency, National Vehicle and Fuel Emissions Laboratory, 2565 Plymouth Road, Ann Arbor, Michigan, 48105. Telephone: (313) 668-4534. Fax: (313) 741-7869. E-mail: