"On March 3, 2014, the Environmental Protection Agency finalized new ('Tier 3') emission standards for light duty (and some larger) motor vehicles. Light duty vehicles include cars, SUVs, vans, and most pickup trucks. Phase-in of the standards will begin with Model Year 2017. By the time Tier 3 is fully implemented in Model Year 2025, the standards for light duty vehicles will require reductions of about 80% in tailpipe emissions of non-methane organic gases and nitrogen oxides (both of which contribute to the formation of ground-level ozone) and of about 70% in tailpipe emissions of particulates. Ozone and particulates are the most widespread air pollutants in the United States. Both contribute to respiratory illness and premature mortality. EPA estimates that implementation of the standards will reduce premature mortality by 770 to 2,000 persons annually, as well as providing reductions in hospital admissions, lost work days, school absences, and restricted activity days for persons with respiratory illness. Assigning monetary values to these benefits, EPA estimates the annual benefits at between $6.7 billion and $19 billion in 2030."
CRS Report for Congress, R43497
The National Agricultural Law Center: http://www.nationalaglawcenter.org/