“The Hard-Look Mandate on Steroids” – Texas Corn Producers v. EPA and the Fifth Circuit’s Expanded Duty to Tackle Statistical Critiques in Rulemaking

1. Introduction

Texas Corn Producers v. EPA, No. 24-60209 (5th Cir. June 24 2025), pits a coalition of corn and sorghum growers together with the Texas fuel-supply industry against the U.S. Environmental Protection Agency (“EPA”). The petitioners attacked EPA’s 2024 rule (“Ra Rule”) that set the Ra factor – a numeric adjustment embedded in federal fuel-economy equations – at 0.81. They argued that an erroneously low Ra factor quietly tightened Corporate Average Fuel Economy (“CAFE”) standards, dampening national gasoline demand and thereby harming farmers and fuel sellers.

The Fifth Circuit agreed. In an opinion by Judge Jerry E. Smith the court (i) found associational standing grounded in predictable, downstream economic injury, (ii) held the rule arbitrary and capricious because EPA ignored statistically-based comments on sample size, vehicle representativeness and data selection, and (iii) vacated the challenged portions of the rule. The decision meaningfully strengthens agencies’ obligations to confront data-driven criticisms and cements economic-standing doctrine for upstream and downstream market participants.

2. Summary of the Judgment

Standing – The coalition had associational standing: members sell gasoline or its feed-stocks; tighter CAFE standards foreseeably lower gasoline sales; vacatur would likely redress that loss.
APA Violation – EPA’s explanation of the 0.81 value consisted of two cursory paragraphs that failed to engage the commenters’ four core critiques: (1) too small a sample, (2) obsolete vehicle mix, (3) arbitrary inclusion/exclusion of outlier data, and (4) unexplained rejection of manufacturer-supplied data. That omission broke the agency’s duty to take a “hard look.”
Remedy – Vacatur is the default under 5 U.S.C. § 706(2); no “serious possibility” existed that EPA could justify 0.81 on remand, and disruption concerns could not trump statutory text.

3. Detailed Analysis

A. Precedents Cited and Their Influence

Motor Vehicle Manufacturers Ass’n v. State Farm, 463 U.S. 29 (1983)
Reasserted as the lodestar for “hard-look” review – the Fifth Circuit measured EPA’s explanation against State Farm’s requirement of reasoned decision-making.
FCC v. Prometheus Radio Project, 592 U.S. 414 (2021)
Provided the succinct formulation: agency action must be “reasonable and reasonably explained.” The court repeated that phrase verbatim.
Mexican Gulf Fishing Co. v. Department of Commerce, 60 F.4th 956 (5th Cir. 2023)
Supplies the rule that an agency must answer comments that, “if true and adopted, would require a change.” Texas Corn Producers turns that language into a potent weapon for data-heavy comment letters.
Diamond Alternative Energy v. EPA, --- U.S. --- (2025)
Recently decided Article III case used to bolster causation and redressability where regulation predictably cuts fuel demand.
Standing trilogy (Lujan; TransUnion; Department of Commerce v. New York) & Fifth Circuit counterparts (Students for Fair Admissions; Texas Association of Manufacturers)
Supplied analytical scaffolding for associational standing and “substantial risk” doctrine.
Vacatur line of cases – Data Marketing Partnership; Chamber of Commerce v. SEC (“Chamber II”); Texas Medical Association v. HHS – guided the remedy discussion: default=vacatur, rare exceptions only.

B. Court’s Legal Reasoning

Associational Standing
a. Injury: Fuel sellers’ profits correlate directly with gallons sold.
b. Causation: Ra undervalued ⇒ tighter CAFE ⇒ more efficient cars ⇒ fewer gallons sold.
c. Redressability: Vacatur likely relaxes CAFE stringency and restores at least some sales. Recent SCOTUS precedent (Diamond Alternative Energy) made this inference “predictable.”
Arbitrary & Capricious Review
• The court inspected the administrative record and found no answer to pivotal statistical objections – a textbook State Farm violation.
• Key Failings:
- Sample size: 11 vehicles cannot support a fleet-wide coefficient when EPA’s own 1995 guidance said 75-100.
- Technological representativeness: vehicles were MY 2013-16; commenters showed drivetrain trends had already shifted.
- Outlier handling: EPA dropped a high-Ra Acura for being “unexpected” yet kept a Malibu with a fault code that pulled Ra down.
- Alternative data: EPA solicited, then ignored, manufacturer certification datasets from 95 newer vehicles – a procedural bait-and-switch.
Remedy
Applying the Chamber II two-step test the court saw no serious prospect of EPA defending 0.81 once it grapples with the ignored critiques, and disruption concerns could not override § 706(2). Vacatur therefore followed.

C. Likely Impact on Future Litigation and Regulation

Elevated Evidentiary Expectations – Agencies relying on proprietary “in-house” testing must anticipate objections on statistical power, representativeness and outlier treatment; silence will be fatal.
Economic Standing Road-map – The opinion, coupled with Diamond Alternative Energy, entrenches a relatively plaintiff-friendly route for upstream or downstream market actors to challenge environmental or efficiency regulations.
Vacatur Default Cemented in Fifth Circuit – Texas Corn Producers confirms the court’s resistance to “remand-without-vacatur” unless both prongs of the Chamber II test are clearly met.
Practical Effect on CAFE / “Gas Guzzler” Administration – Until EPA re-proposes, manufacturers remain free to continue using E0 test fuel or to self-select an R-value under existing 1986 guidance, potentially increasing compliance flexibility and slowing the transition to E10 testing.
Signal to Statistical Commenters – Detailed quantitative submissions (like those by the Alliance and Biofuels Coalition) now demonstrably carry litigation clout; trade groups will invest more in technical comments.

4. Complex Concepts Simplified

CAFE Standards – Fleet-average miles-per-gallon targets set by NHTSA; failure triggers fines, success generates tradable credits.
Gas Guzzler Tax – An Internal Revenue Code tax ($1,000–$7,700 per car) on passenger vehicles achieving < 22.5 mpg.
R vs. Ra Factor
• R (1986) – Adjusts for lower energy density when ethanol blends are used in testing; assumed older engines captured only 60 % of energy change.
• Ra (2024) – Updated adjustment intended to bundle both energy-content effects and other chemistry variances (octane, heat-of-vaporization). EPA set Ra = 0.81; petitioners say modern engines are ≈ 1.0.
Footprint Curve – CAFE target for each vehicle is a function of its wheelbase × track width; larger “footprint” means laxer individual target but leaves fleet-average calculus intact.
Hard-Look Review – Courts verify that agencies “examine all relevant data and articulate a satisfactory explanation”; ignoring significant counter-evidence violates this duty.

5. Conclusion

Texas Corn Producers v. EPA crystallises two doctrinal currents. First, it confirms that any rule capable of predictably shrinking product demand inflicts Article III injury on suppliers, clearing the courthouse door for industry challenges. Second, it supercharges State Farm’s hard-look requirement: statistical criticisms about sample size, representativeness and data integrity sit at the core of “relevant factors” that agencies must confront. By vacating the Ra Rule outright—and doing so despite the Agency’s plea for a voluntary remand—the Fifth Circuit signals an unforgiving stance toward cursory regulatory justifications, especially where technical data are concerned.

Going forward, environmental and energy regulators must treat comment-period data not as peripheral chatter but as a central evidentiary record to be directly and transparently engaged. Failure to do so may send their rules back to the drawing board—Ra-zed to the ground by judicial review.