The White House announced Wednesday that the Environmental Protection Agency on Thursday will revoke a scientific finding that led to greenhouse gas regulations impacting truck manufacturers and trucking writ large, along with other vehicle makers.
White House Press Secretary Karoline Leavitt in her daily press conference said President Trump and EPA Administrator Lee Zeldin on Thursday will “formalize the rescission of the 2009 Obama-era Endangerment Finding,” of which Zeldin called for revocation last summer.
Zeldin then claimed rescinding the Endangerment Finding and resulting regulations would end $1 trillion or more "in hidden taxes on American businesses and families.”
A “Legal Sidebar” published June 6, 2025, by the Congressional Research Service (CRS) related to EPA’s plan to revisit the Endangerment Finding noted that “EPA action on the Endangerment Finding could call into question the legitimacy of GHG standards for automobiles, power plants, and oil and gas sector facilities, which rely, in part, on the Endangerment Finding.”
CRS added, however, that repealing the Endangerment Finding “would not, by itself, repeal those later-issued regulations,” including all Biden- and Obama-era greenhouse gas standards for light-, medium- and heavy-duty vehicles and heavy-duty engines.
[Related: DOJ policy shift on diesel 'deletes': Owner-ops wary of civil enforcement]
“EPA has announced that it intends to separately reconsider its operative GHG standards,” CRS added in its Legal Sidebar. “It is uncertain whether or how EPA’s reconsideration of the Endangerment Finding will inform its review of those other rules.”
EPA said in November it’s planning to move forward with its GHG Phase 3 regulations taking effect with the 2027 model year, but noted that it’s planning “major changes" to the program requirements.
As reported last summer by Overdrive sister publication CCJ, engineering has long been underway on diesel engines that will meet those 2027 emissions regulations. Many aftertreatment systems have been completely redesigned, electrical systems and engines re-engineered, and an entirely new diesel engine oil category has been implemented to reach compliance.
The latest move on the Endangerment Finding follows other recent significant emissions-related moves around the Trump administration, from the Department of Justice backing off criminal prosecution of emissions-'delete' shops and owners to EPA signaling a potential end to engine derates in the event of emission-control malfunctions.
