The Clean Car Standards: Background and Frequently Asked Questions

The clean car standards, initiated by California's AB 1493 and adopted by the California Air Resources Board (CARB), comprise regulations for air quality, global warming, and zero-emission vehicles. These standards aim for a 30% reduction in global warming pollution from new vehicles by 2016 and are more stringent than federal Corporate Average Fuel Economy (CAFE) standards, targeting a fleet average fuel economy equivalent of 39.2 mpg by 2020 compared to the federal 35 mpg. As of January 2009, 13 states and the District of Columbia had adopted these standards, which are projected to reduce cumulative global warming emissions by 451 million metric tons of CO2E by 2020 across those 15 jurisdictions.

• The clean car standards consist of three regulatory areas: air quality standards limiting soot and smog-forming pollutants; global warming standards regulating carbon dioxide, methane, and air conditioning refrigerants; and Zero-Emission Vehicle standards requiring the production of battery-electric, hydrogen fuel-cell, and ultra-clean gasoline vehicles.
• The global warming standards target vehicles weighing under 10,000 pounds and were designed to achieve a 30% reduction in global warming pollution from new vehicles by 2016. A second phase, known as the "Pavley 2 Standards," is intended to regulate fleet-wide emissions from 2016 through 2020.
• The clean car standards are more ambitious than the federal Corporate Average Fuel Economy (CAFE) standards established by the 2007 Energy Independence and Security Act. While federal standards require a minimum fleetwide average of 35 mpg by 2020, the California standards' estimated equivalent is 39.2 mpg. Additionally, the clean car standards address air conditioning refrigerant leakage and component efficiency, which CAFE standards do not.
• As of the document's publication, 13 states (Arizona, Connecticut, Maine, Maryland, Massachusetts, New Jersey, New Mexico, New York, Oregon, Pennsylvania, Rhode Island, Vermont, and Washington) and the District of Columbia have adopted the standards. Implementation across these 15 jurisdictions is projected to reduce cumulative global warming emissions by 451 million metric tons of CO2E by 2020, representing a 43% improvement over proposed federal CAFE standards.

APA

Union of Concerned Scientists (2009). The Clean Car Standards: Background and Frequently Asked Questions. https://www.ucs.org/sites/default/files/2019-10/clean-car-standards.pdf

Chicago

Union of Concerned Scientists. The Clean Car Standards: Background and Frequently Asked Questions. 2009. https://www.ucs.org/sites/default/files/2019-10/clean-car-standards.pdf.

Wikipedia

{{cite report |author=Union of Concerned Scientists |title=The Clean Car Standards: Background and Frequently Asked Questions |date=January 2009 |url=https://www.ucs.org/sites/default/files/2019-10/clean-car-standards.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{unionofconcernedscientists2009clean, author = {{Union of Concerned Scientists}}, title = {{The Clean Car Standards: Background and Frequently Asked Questions}}, institution = {Union of Concerned Scientists}, year = {2009}, month = jan, url = {https://www.ucs.org/sites/default/files/2019-10/clean-car-standards.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }