The U.S. Environmental Protection Agency (EPA) is seeking public feedback on proposed revisions to its 2023 heavy-duty truck emissions rule, allowing truck drivers, owner-operators, fleets, manufacturers, and other stakeholders to comment before changes are finalized.
The proposal focuses on several compliance requirements affecting model year 2027 and newer trucks but does not change the nitrogen oxide (NOx) emissions standards established under the original rule.
EPA Proposes Changes to Several Compliance Requirements
The EPA’s 2023 rule introduced new emissions requirements for model year 2027 heavy-duty trucks, including nitrogen oxide standards that are 80 percent stricter than previous federal limits.
As part of its latest proposal, the agency is recommending changes to several compliance provisions, including:
- Replacing mandatory engine derates with audible or visual warning systems when diesel exhaust fluid (DEF) issues are detected.
- Returning the emissions compliance period from 650,000 miles to 435,000 miles.
- Returning emissions-related warranty coverage from 10 years or 450,000 miles to five years or 100,000 miles.
The proposed revisions would leave the underlying NOx emissions standards unchanged.
Industry Response Has Been Mixed
Many trucking organizations welcomed the proposed changes to engine derates and compliance requirements. However, the Owner Operator Independent Drivers Association (OOIDA) expressed concern that the proposal does not address the emissions standards themselves.
OOIDA also criticized the proposal to shorten emissions-related warranty coverage, arguing that reduced warranty protection could leave owner-operators and small carriers responsible for costly repairs involving emissions systems.
“If EPA is unable to amend burdensome NOx emissions standards, we believe there are more productive solutions than drastically cutting extended warranty periods for small business truckers at the behest of engine manufacturers and large fleets,” said Jay Grimes, OOIDA’s director of federal affairs.
Grimes added that warranty coverage should continue protecting truck owners from repeated and expensive emissions system failures that drivers have reported under previous emissions regulations.
Public Comment Period Runs Through August 29
The EPA is accepting public comments on the proposal through Aug. 29, 2026.
Drivers and other stakeholders can submit comments through Regulations.gov using docket number EPA-HQ-OAR-2026-0728.
The agency will also hold two virtual public hearings:
- July 29 at 9 a.m. Eastern.
- July 30 at 10 a.m. Eastern.
Anyone wishing to testify must register in advance by emailing [email protected]. According to the EPA, registration forms for those planning to testify must be submitted by July 22.
The agency will review public comments before determining whether to finalize the proposed revisions.
The TDUSA editorial team creates practical, driver-focused content covering trucking news, industry updates, safety, regulations, and career information for professional truck drivers across the United States. Each article is built to reflect real-world experience, industry developments, and information drivers can use on and off the road.
Last Updated: July 21, 2026
Source: Land Line Media








