Gasoline Frequently Asked Questions
1. How much ethanol is required in California gasoline?
None. California Reformulated Gasoline (CaRFG3) regulations do not require the use of ethanol. However, ethanol is an oxygenate, and there is an oxygen content requirement.
2. How much oxygen is required in California gasoline?
There is a minimum oxygen content requirement of 1.8 percent by weight for the South Coast area and Imperial County, from November 1st through February 29th. Outside of that requirement, refiners have the option to put from 0-3.5 percent by weight oxygen (0-10 volume percent ethanol) in CaRFG3.
3. How much ethanol is in the gasoline I buy in California?
Currently, most gasoline contains 10 percent ethanol by volume. For a detailed breakdown of the CaRFG3 specifications, please review our gasoline specifications and test methods specification summary. For information about other gasoline specifications, please visit our Alternative Fuels page.
4. When did California last change its gasoline requirements?
The California Air Resources Board last approved amendments to the CaRFG3 regulations in June 2007. The most recent amendments took effect beginning December 31, 2009.
5. What changes did the most recent amendments make?
The amendments updated the Predictive Model requirements (determines which gasoline formulations comply) and mitigate permeation emissions from the ethanol used in gasoline vehicles. For more details on the changes, see the CaRFG3 Rulemaking page.
6. Can warmer month gasoline blends also be used outside of the required regulatory control period (warmer months) specified in Title 13, California Code of Regulations (CCR) section 2262.4?
Yes, gasoline blends meeting the warmer month requirements including the Reid Vapor Pressure (RVP) specified in Title 13, CCR section 2262 can be supplied and sold outside of the regulatory control period (e.g., warmer months) identified in section 2262.4.
Updated February 20, 2025