Amendments and Nonconformance Penalties for Model Year 2027 and Later Heavy-Duty Highway Engines and Amendments to Inducement Provisions for SCR-Equipped Diesel Engines

What it does

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.

The Environmental Protection Agency's summary, as published in the Federal Register.

What it would change

6 parts of Title 40 of the Code of Federal Regulations:

40 CFR 86, 40 CFR 1036, 40 CFR 1037, 40 CFR 1039, 40 CFR 1065, 40 CFR 1071

Before this

No earlier Federal Register document under regulation identifier 2060-AW83 since Jan. 1, 2025.

What happens next and when

Comments. Comments must be received on or before August 29, 2026. Comments on the information collection provisions submitted to the Office of Management and Budget (OMB) under the Paperwork Reduction Act (PRA) are best assured of consideration by OMB if OMB receives a copy of your comments on or before August 13, 2026.

The agency's dates, word for word.

Check it yourself

• The document in the Federal Register
• Docket EPA-HQ-OAR-2026-0728 on Regulations.gov
• Title 40 on eCFR

The record as published

Source: the Federal Register (public domain). The document in the Federal Register