The Renewable Fuels Association (RFA) has urged the California Air Resources Board (CARB) to quickly finalise regulations allowing the sale of E15, saying the higher-ethanol blend could reduce fuel costs for consumers and expand gasoline supply in the state, according to a press release.
In comments submitted to CARB, RFA said E15 could provide California motorists with a lower-cost fuel option while using ethanol as a low-carbon, high-octane and cost-competitive blending component. CARB is scheduled to hold a hearing and vote on adopting the E15 regulation next week.
RFA Director of Regulatory Affairs Maddie Jenks said expanding E15 availability would give consumers another gasoline option, increase the pool of available fuel supply and provide greater flexibility to California’s gasoline market.
She also said prompt finalisation of the regulation would provide suppliers, terminals, fuel marketers and retailers with the regulatory certainty needed to make investment and supply decisions, allowing E15 to reach consumers as soon as possible.
The push comes as gasoline prices in California remain the highest in the US. AAA reported the state’s average gasoline price at more than $6 per gallon.
RFA cited analysis by economists at the University of California, Berkeley and the US Naval Academy, which estimated that E15 could lower gasoline prices for California consumers by around 20 cents per gallon, generating approximately $2.7 billion in annual consumer savings.
RFA also cited a more recent analysis by an independent petroleum refining expert, which found that the national average cost advantage of E15 had averaged 57 cents per gallon since the beginning of the Iran conflict.
The association urged CARB to coordinate with the state fire marshal on the compatibility of vapor recovery equipment with E15. RFA said equipment implementation should continue alongside, rather than delay, finalisation of the fuel regulation.
According to Jenks, California has already completed substantial technical work required to establish permanent E15 requirements. The state Legislature has unanimously authorised E15, while CARB has completed its multimedia evaluation and California-specific emissions testing and developed a regulatory framework for incorporating E15 into the existing gasoline programme.
RFA has been working with CARB on E15 testing and analysis since 2018.
The association supports CARB’s proposal to regulate E15 as gasoline under the existing California Reformulated Gasoline (CaRFG) framework rather than classify it as a separate alternative or specialty fuel.
RFA also supports proposed amendments establishing oxygen-content standards for E15, maintaining multiple pathways for blending the fuel, using existing federal E15 labelling requirements instead of introducing a separate California-specific label, and not creating a separate octane-posting requirement specifically for E15.
RFA has participated throughout CARB’s E15 rulemaking process, including submitting comments following the board’s November 2025 E15 Scoping Workshop. The association had called for E15 to be incorporated into California’s existing gasoline programme while allowing suppliers flexibility in how the fuel is produced and distributed.
