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EPA Releases Proposed Clean Trucks Rule

WASHINGTON- Earlier this week, the Biden Administration released details on its proposed plan to address emissions from medium- and heavy-duty vehicles.

The regulatory actions that make up the U.S. Environmental Protection Agency’s (EPA) Clean Trucks Plan are as follows:

  • Setting stronger nitrogen oxide (NOx) standards for heavy-duty trucks beginning in model year (MY) 2027 and tightening the “Phase 2” greenhouse gas (GHG) emissions for MY 2027 and beyond.
  • Setting stronger emissions standards for medium-duty commercial vehicles for MY 2027 and later.  These revised standards will be proposed in combination with new standards for light-duty vehicles for MY 2027 and beyond.
  • Setting “Phase 3” GHG standards for heavy-duty vehicles beginning as soon as MY 2030 that are significantly stronger than the MY 2027 GHG standards.

The plan offers two proposed options to meet the more stringent NOx standard component:

  • Under the proposal, engine and truck manufactures certifying under Option 1 would be required to lower emissions in two steps and would be required to meet reduce nitrogen oxide emissions by 90 percent in 2031 (to 0.02 g/bhp-hr). 
  • Option 2 would require nitrogen oxide emissions by 75 percent beginning in 2027 (to 0.05 g/bhp-hr).   

The emission levels – 0.02 and 0.05 g/bhp-hr – represent a significant reduction from the current 0.2 standard that has been in place since 2010. 

EPA also has proposed other changes in this rulemaking including adjusting testing cycles to be more representative of in-use operating conditions, extending durability requirements and warranty coverage. 

The proposed greenhouse gas emission changes in this rulemaking would starting in 2027 address standards for 17 of the 33 subcategories of vocational and tractor vehicles would include changes for school buses, transit buses, commercial delivery trucks, and short-haul tractors. 

The EPA webpage for the proposed rule and related materials can be found at:

The full notice is available at:

Comments are due 46 days from publication in the Federal Register.  NGVAmerica has begun its process to develop a group industry comment.

EPA’s Sarah Dunham, Director of the Office of Transportation and Air Quality, is confirmed to brief NGVAmerica members on details of this proposed rule at our DC Fly-In Advocacy Days scheduled for April 5th and 6th.  Full agenda and registration information available here.