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WEDNESDAY, JULY 29, 2026   |   SPECIAL REPORT & ANALYSIS

BIOFUELS POLICY  |  CALIFORNIA E15

California Finally to Write the Rules for E15 — But the Pump is Still a Long Way Off

CARB’s Sept. 24 vote would clear one of the two hurdles still standing between the nation’s No. 2 gasoline market and a fuel that saves drivers 20 to 40 cents a gallon — but the fire marshal’s vapor-recovery mandate, and the biofuel lobby’s own track record of missed California timelines, argue for keeping expectations in check.
 

Analysis  ·  July 29, 2026
 

The California Air Resources Board (CARB) on Sept. 24 will consider adopting the E15 fuel specifications the state needs before gasoline blended with 15% ethanol can legally flow from retail pumps — the last major CARB milestone in a saga that began with a multimedia evaluation in 2018 and produced a unanimous legalization law last fall. Ethanol groups cheered the proposal, and they should: it is real, overdue progress. But a close look at the record suggests the industry’s celebratory press releases deserve the same discount the market applies to any forecast that has repeatedly slipped. E15 sales in California at any meaningful scale remain, most likely, a 2027 story — and possibly later.

Legalization was the easy part. California’s E15 saga has become a case study in the distance between a bill-signing ceremony and a working fuel pump.

What CARB proposed, and what it actually does

The mechanics: CARB’s proposed rulemaking would amend the California reformulated gasoline (CaRFG) regulations to establish fuel specifications and test-method standards for gasoline blended with 15% ethanol, formally folding E15 into the state’s fuel-quality regime. The board hearing is set for 9 a.m. Pacific on Thursday, Sept. 24, in Sacramento, with in-person and Zoom participation, following the standard 45-day public comment window. If the board adopts the package, it still must clear the Office of Administrative Law before taking effect — a step that typically pushes the effective date months beyond the vote.

The usual cheering came from U.S. biofuel groups. Growth Energy and the Renewable Fuels Association (RFA), the two largest U.S. ethanol trade groups, praised the release. “CARB’s proposed rulemaking represents a critical step toward getting E15 into the fuel tanks of California drivers, who are looking for ways to save money,” said Growth Energy CEO Emily Skor. RFA President and CEO Geoff Cooper noted that “E15 is selling for 20-40 cents per gallon less than E10 where it is being offered today,” adding that “California drivers are missing out on these savings all because of unnecessary regulatory burdens and inaction by the fire marshal’s office.”

Why that last clause matters: the CARB rulemaking is necessary but not sufficient. Even a smooth Sept. 24 adoption leaves a second, independent gate standing — the State Fire Marshal’s equipment-certification requirement — and that gate, not CARB, now looks like the binding constraint on when Californians actually see E15 at retail.

Why the stakes are big for ethanol and corn

California burns roughly 13.5 billion gallons of gasoline a year, second only to Texas, and its standard gasoline is capped at 10% ethanol (flex-fuel E85 aside). Ethanol groups peg the California E15 opportunity at 600 million to 800 million gallons of incremental annual ethanol demand — equivalent to roughly 250 million bushels of corn, by the Iowa Renewable Fuels Association’s (IRFA) math. For an industry staring at flat domestic gasoline demand and policy uncertainty around year-round E15, it is the largest single untapped market left in the country.

The consumer math is similarly attractive. A study by UC Berkeley and U.S. Naval Academy economists, cited throughout the AB 30 debate, projected statewide E15 availability would trim pump prices by about 20 cents a gallon and save California drivers roughly $2.7 billion a year — about $200 per household — in a state with the nation’s most expensive gasoline. Real-world data from functioning E15 markets brackets that estimate: Minnesota’s 2024 average discount was 18 cents versus E10, while RFA says current discounts run 20 to 40 cents where E15 is offered today.

Figure 1. E15’s per-gallon discount to regular gasoline: observed market data and the projection for California. Sources: RFA; Minnesota Department of Commerce data via RFA; UC Berkeley/U.S. Naval Academy study.

Meanwhile, the rest of the country keeps demonstrating what California is missing. U.S. E15 sales jumped 23% in 2025 to a record 1.52 billion gallons, and the station count grew by 900 — as many as the prior two years combined — to about 4,600 nationwide. Iowa alone sold more than 410 million gallons (up 60%, driven by its E15 access standard), and Minnesota moved 169 million gallons.

Figure 2. National E15 sales and station counts keep setting records. Source: RFA analysis, April 2026.

Figure 3. E15 is legal in all 50 states; Iowa and Minnesota anchor the market while California remains the only state with zero retail sales. Sources: RFA; California AB 30.

The fire marshal’s roadblock

The hurdle that has turned a nine-month-old law into zero gallons sold sits in an office most fuel-policy watchers had never mapped: the California State Fire Marshal. California is the only state that still requires enhanced (Stage II-style) vapor recovery systems at the pump, and the fire marshal has taken the position that E15 cannot be dispensed until those systems are formally certified as compatible with the fuel — a certification process IRFA warns could take two years.

The industry’s counterarguments are substantive. Modern vehicles carry onboard refueling vapor recovery, which is why the U.S. EPA allowed every other state to decommission Stage II equipment years ago — some research suggests running both systems simultaneously can actually increase emissions. Equipment manufacturers have stated their hardware is compatible with E15, and the components were already exposed to E15 during their original E10-era testing. “We continue to believe the fire marshal should accept manufacturer statements regarding the compatibility of their vapor recovery equipment with E15,” Cooper said Wednesday, noting conversations are ongoing with the fire marshal, the governor’s office, manufacturers, CARB and fuel retailers. Growth Energy says it is working the same channels.

But the fire marshal has shown little urgency. “The state fire marshal has dug in. They don’t seem like they’re ready to move,” RFA’s Robert White told an industry audience in June. RFA has asked the state to use enforcement discretion — allowing E10-certified equipment to dispense E15 while formal certification proceeds — and so far has not gotten it. IRFA Executive Director Monte Shaw was blunter in July, accusing “one bureaucrat” of turning “a win-win into a lose-lose.”

The lobby’s timeline problem: wrong before, and why

Here is the uncomfortable context for this week’s celebratory statements: the U.S. biofuel lobby has been persistently — and materially — too optimistic about California E15 timelines for the better part of a decade. That does not make the groups wrong about the fuel’s merits. It does mean their implied schedules should be treated as advocacy, not analysis.

Table 1. California E15: what the industry expected vs. what happened

Why has the biofuel lobby kept missing the timeline?

Three recurring analytic errors stand out.

First, conflating legalization with implementation. Ethanol advocates treated each political victory — the completed multimedia evaluation, unanimous floor votes, the governor’s signature on an urgency statute — as the moment E15 “arrived.” But in California, a statute is an instruction to agencies, not a fuel spec. The Administrative Procedure Act rulemaking now underway, with its comment periods, board hearing and OAL review, was always going to consume a year or more after AB 30; that was knowable on signing day, and largely absent from the victory laps.

Second, mapping the wrong agencies. The industry spent years courting CARB — reasonably, since CARB owned the multimedia evaluation. But the binding constraint turned out to be the State Fire Marshal, an office with no stake in fuel-market economics, applying an equipment rule no other state retains. The lesson generalizes: in a state with layered, semi-independent regulators (CARB, the fire marshal, the Department of Food and Agriculture’s measurement-standards division), clearing the agency you know is not the same as clearing the state.

Third, the incentive to project momentum. Trade associations exist to signal progress to members and pressure regulators with inevitability. That produces systematically rosy timelines — particularly in a state whose regulatory culture is precautionary by design and whose energy agenda is organized around electrifying the vehicle fleet by 2035, not optimizing the liquid-fuel pool. A gasoline additive, however cost-saving, was never going to be a priority docket in Sacramento, and treating it as one led the lobby to under-forecast every interval in this process.

What to watch from here

The Sept. 24 board vote is the next checkpoint, and approval looks likely given CARB’s own findings that E15 modestly reduces emissions relative to E10. From there, watch the OAL clock for the rule’s actual effective date, and — more importantly — watch for any movement by the fire marshal toward accepting manufacturer compatibility statements in lieu of a multi-year certification. That single administrative choice is worth more to 2027 California E15 volumes than anything CARB does in September.

The federal backdrop matters too. Nationwide E15 sold this summer only under EPA emergency waivers issued in rolling 20-day increments starting May 1. A permanent fix — the Nationwide Consumer and Fuel Retailer Choice Act (HR 1346), which pairs year-round E15 with small-refinery-exemption reforms — passed the House 218-203 on May 13 but awaits Senate action. A California market that finally opens in 2027 would be worth far more to ethanol producers if year-round certainty is law by then.

Table 2. Plausible timelines for first California E15 sales

Bottom line

CARB’s Sept. 24 vote is genuine progress and probably the last significant hurdle inside CARB itself — but it is not the moment E15 “arrives” in California, and the industry’s own history there counsels discounting any implied schedule. The binding constraint is now the fire marshal’s vapor-recovery certification, an issue almost no one in the ethanol lobby was talking about a year ago. Corn and ethanol markets should treat California demand — 600-800 million gallons of potential ethanol pull, roughly 250 million bushels of corn — as a 2027-and-beyond story, with real upside if Sacramento accepts manufacturer compatibility statements and real risk of 2028 if it does not.

AG POLICY & MARKETS DAILY   |   BIOFUELS POLICY  |  CALIFORNIA E15 — WEDNESDAY, JULY 29, 2026