Environmental Protection Agency
The U.S. Environmental Protection Agency (EPA) is proposing regulatory amendments to certain compliance provisions and test procedures related to model year (MY) 2027 and later heavy-duty highway engines. These amendments would include changes to the regulatory useful life periods and the emission-related warranty periods. The EPA also proposes to add clarity to certain regulatory compliance provisions and correct errors in the regulations to support the MYs 2027 and later program for heavy-duty highway engines and vehicles. This includes certain amendments related to provisions adopted in January 2023 as well as other provisions adopted in earlier rules. The EPA also proposes to make nonconformance penalties (NCPs) available to manufacturers of medium heavy-duty engines (Medium HDE) and heavy heavy-duty engines (Heavy HDE) beginning in MY 2027. In addition, the EPA proposes to amend the requirements for selective catalytic reduction (SCR) system inducement provisions for newly manufactured diesel-fueled highway engines and vehicles (i.e., light- and medium- duty vehicles and heavy-duty engines) and nonroad engines and equipment. The EPA is also considering new inducement guidance for in- use highway and nonroad diesel engines, vehicles, and equipment.
Document Headings Document headings vary by document type but may contain the following: the agency or agencies that issued and signed a document the number of the CFR title and the number of each part the document amends, proposes to amend, or is directly related to the agency docket number / agency internal file number the RIN which identifies each regulatory action listed in the Unified Agenda of Federal Regulatory and Deregulatory Actions See the Document Drafting Handbook for more details. Environmental Protection Agency 40 CFR Parts 86, 1036, 1037, 1039, 1065, and 1071 [EPA-HQ-OAR-2026-0728; FRL 12756-01-OAR] RIN 2060-AW83 ( printed page 43154) AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed rule. SUMMARY: The U.S. Environmental Protection Agency (EPA) is proposing regulatory amendments to certain compliance provisions and test procedures related to model year (MY) 2027 and later heavy-duty highway engines. These amendments would include changes to the regulatory useful life periods and the emission-related warranty periods. The EPA also proposes to add clarity to certain regulatory compliance provisions and correct errors in the regulations to support the MYs 2027 and later program for heavy-duty highway engines and vehicles. This includes certain amendments related to provisions adopted in January 2023 as well as other provisions adopted in earlier rules. The EPA also proposes to make nonconformance penalties (NCPs) available to manufacturers of medium heavy-duty engines (Medium HDE) and heavy heavy-duty engines (Heavy HDE) beginning in MY 2027. In addition, the EPA proposes to amend the requirements for selective catalytic reduction (SCR) system inducement provisions for newly manufactured diesel-fueled highway engines and vehicles ( i.e., light- and medium-duty vehicles and heavy-duty engines) and nonroad engines and equipment. The EPA is also considering new inducement guidance for in-use highway and nonroad diesel engines, vehicles, and e…
Citation: 91 FR 43154
