The EPA is promulgating new GHG emissions standards for model year (MY) 2032 and later heavy-duty highway vehicles that phase in starting early MY 2027 for certain vehicles. The phase revises certain MY 2027 GHG standards that were established previously under EPA's DHD Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles--Phase 2 rule. This document also updates elements of the Averaging Banking and Trading program, including providing flexibilities for manufacturers to support the implementation of the Phase 3 program balanced by limiting the availability of certain advanced technology credits initially established under the HD GHG Phase 2 rule. EPA is also adding warranty requirements for batteries and other components of zero-emission vehicles and requiring customer-facing battery state-of-health monitors for plug-in hybrid and battery electric vehicles. In this action, we are also finalizing additional revisions, including clarifying and editorial amendments to certain highway heavy-duty vehicle provisions and certain test procedures for heavy-duty engines. This final rule is effective on 21 June 2024. POC is Brian Nelson, Assessment and Standards Division, Office of Transportation and Air Quality, EPA, 2000 Traverwood Drive, Ann Arbor, MI 48105; tele: (734) 214-4278; email: nelson.brian@epa.gov.

(Federal Register 22 April 2024 [Rule] Pages 29440-2983)