California Reformulated Gasoline

This page last reviewed July 15, 2015

As part of an overall program to reduce emissions from motor vehicles, the Air Resources Board implemented the first phase of California Reformulated Gasoline requirements in January, 1992.

Phase 1 Reformulated
Gasoline (CaRFG1)

CaRFG1 modified the requirements for Reid Vapor Pressure (RVP) content, required additives in gasoline, and decreased allowable lead content. For more information or to view the regulation, please visit our CaRFG1 web page.

Phase 2 Reformulated
Gasoline (CaRFG2)

CaRFG2 was introduced into the marketplace on March 1, 1996. By lowering previously regulated components (Reid vapor pressure and sulfur content), requiring the use of oxygenates year-round, and regulating additional components (benzene, total aromatics, olefins, and distillation temperatures T50 and T90), gasoline emissions were decreased to their lowest levels to date. In addition to reducing smog-forming emissions, the use of reformulated gasoline also reduced carcinogenic toxic air contaminants by more than a third. For more information or to view the regulation, please visit our CaRFG2 web page.

Phase 3 Reformulated
Gasoline (CaRFG3)

CaRFG3 regulations were approved in May, 2003 by the Office of Administrative Law. Changes to the regulations included the proposed removal of MTBE without any reduction in the emissions benefits of the existing program. Other changes included refinery limits and cap limits for every regulated property as well as changes to the RVP season. A list of the effective transitional dates for CaRFG3 can be viewed at Phase 3 CaRFG Limits. For more information or to view the regulation, please visit our CaRFG3 web page.

Fuels Specifications and Test Methods

As a supplement to the regulation, tables which list the regulated properties and test limits of CaRFG, motor ethanol, and diesel fuel are available at:

Gasoline Specifications
and Test Methods

Motor Ethanol Standards
and Test Methods

Diesel Fuel Specifications
and Test Methods

These brief summaries are not legal documents and are not intended to be used in lieu of the regulation, but as an aide to understanding the specifications and limits of the fuels' regulated properties.

Background Material

A 2003 Assessment of the Impacts of CaRFG (pdf 804K) has indicated that the benefits of the program have been equivalent to the removal of 3.5 million vehicles from California's roads. More detailed information about CaRFG regulations, the study of gasoline price and supply, and listings of meetings and activities, is available at the ARB's California Gasoline Program web page.

Contact Us

For more information regarding the enforcement of CaRFG regulations, please email Mark Stover, Branch Chief, Field Operations Branch, or telephone (916) 229-0757. For more information regarding other Enforcement Programs, please visit our Enforcement Program Contacts web page.