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EPA to Revisit GHG 3, NOx Emissions Regs

The trucking industry is applauding a move by the U.S. Environmental Protection Agency to revisit the Greenhouse Gas Phase 3 regulations for commercial vehicles, which have been criticized as a de facto zero-emission truck mandate.

March 12, 2025
EPA to Revisit GHG 3, NOx Emissions Regs

The EPA is revisiting truck tailpipe and greenhouse gas emissions regulations.

Photo: Mack Trucks (from files)

3 min to read


As many have expected, the U.S. Environmental Protection Agency announced it will revisit the Greenhouse Gas Phase 3 regulations for commercial vehicles, which have been criticized as a de facto zero-emission truck mandate.

EPA Administrator Lee Zeldin announced the agency will reconsider the Model Year 2027 and Later Light-Duty and Medium-Duty Vehicles regulation and Greenhouse Gas Emissions Standards for Heavy-Duty Vehicles. 

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Finalized just last year, the GHG 3 rules would apply to medium- and heavy-duty vocational vehicles (such as delivery trucks, refuse haulers, public utility trucks, transit, shuttle, and school buses) and tractors (such as day cabs and sleeper cabs on tractor-trailer trucks):

  • Light Heavy-Duty (Class 2b-5)

  • Medium Heavy-Duty (Class 6-7)

  • Heavy Heavy-Duty (Class 8)

EPA said in the final rule that it anticipates that a compliant fleet under the final standards will include a diverse range of technologies, including ZEV and ICE vehicle technologies.

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However, the American Trucking Associations and other critics said the timeline involved would essentially require truck and engine makers to sell an increasingly higher percentage of zero-emission vehicles.

Additionally, EPA said it is reevaluating the 2022 Heavy-Duty Nitrogen Oxide (NOx) rule.

The American Trucking Associations started lobbying the Trump Administration to prioritize the reopening of the Greenhouse Gas Phase 3 even before President Trump took office.

Trucking Responds to EPA Revisiting Truck Emissions Rules

American Trucking Associations President and CEO Chris Spear praised the move in a statement. 

“GHG3 in its current form is unachievable given the state of battery-electric technology and the sheer lack of charging infrastructure,” Spear said.

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“This rule has been an albatross for the trucking industry, threatening to reduce equipment availability, increase costs for businesses and consumers, and cause major supply chain disruptions.

“It is critically important that the federal government set realistic standards with achievable targets and timelines.  

“Prior to the imposition of GHG3, EPA used a collaborate process that served the agency and the trucking industry well and allowed us to make monumental progress to reduce emissions.  As a result, 60 trucks today emit the same amount as one truck manufactured in 1988.  

“The trucking industry welcomes the resumption of this productive partnership with EPA.”

Small-Business Truckers, RNG Advocates Applaud

The Owner-Operator Drivers Association was happy, as well.

“Small-business truckers make up 96% of trucking and could be regulated out of existence if the current standards were to be implemented,” said OOIDA President Todd Spencer in a statement.

“Mom and pop trucking businesses would be suffocated by the sheer cost and operational challenges of effectively mandating zero emission trucks. Vehicle reliability and affordability are top priorities for OOIDA members and we have yet to see proof that electric CMVs are a practical option for most trucking businesses considering the price tag and lack of charging infrastructure.”

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The Transport Project, which promotes the use of renewable fuels, also applauded the announcement, saying the rule was based on incomplete cost estimates and ignored full life cycle impacts.

“The Biden rule unfairly and capriciously manipulated outcomes to advance favored technologies, slowing progress on an all-of-the-above clean vehicle deployment approach and adding unwarranted burdens to trucking fleets that would have resulted in unnecessary and excessive costs for American consumers and families,” said TTP President Dan Gage.

Jim Mullen, executive director of the Clean Freight Coalition, pointed out that the trucking industry has made significant improvements on tailpipe emissions over the last several decades.

“We will work with the administration on reasonable and achievable solutions that continue to deliver cleaner commercial vehicles moving forward,” he said.

“We will also continue to advocate for a national regulatory framework that is technology neutral and achieves the greatest benefit for the environment without unnecessarily burdening the industry, the economy, and all consumers of goods in our country.”

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