On-Road Heavy-Duty Engine and Vehicle Omnibus, Low Carbon Fuel Standard, and Emergency Vehicle Emissions Regulations

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This page last reviewed September 23, 2025

Proposed Amendments to the On-Road Heavy-Duty Engine and Vehicle Omnibus, Low Carbon Fuel Standard Regulations, and to Permanently Adopt the Emergency Vehicle Emissions Regulations

Hearing Date(s)
Public Comments Received
Final Approval / OAL Action

This stage has not yet been reached.

Adopted Regulations and Materials Submitted to OAL

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Public Hearing Notice and Related Material
Posted
Notice of Public Hearing  (Deadline to Submit Public Comments: November 10, 2025, or at the Public Hearing.)
Staff Report: Initial Statement of Reasons
Appendix A-1: Proposed Amendments to Omnibus Title 13 Regulation Order
Appendix A-1-1:  ~(accessible Word version)~
Appendix A-2: Proposed New Section to Omnibus Title 13 Regulation Order
Appendix A-3: Proposed Amendments to Title 13 Sections for the Emergency Vehicle Emissions Regulation
Appendix A-3-1:  ~(accessible Word version)~
Appendix A-4-1: Proposed Adoption of Title 13 Sections for the Emergency Vehicle Emissions Regulation
Appendix A-4-2: Proposed Adoption of Title 13 Sections for the Emergency Vehicle Emissions Regulation
Appendix A-5: Proposed Amendments to Title 17 Sections for the Emergency Vehicle Emissions Regulation
Appendix A-5-1:  ~(accessible Word version)~
Appendix A-6: Proposed Adoption of Title 17 Sections for the Emergency Vehicle Emissions Regulation
Appendix A-7: Proposed LCFS Amendments to Title 17 Regulation Order
Appendix A-7-1:  ~(accessible Word version)~
Appendix B-1: Proposed Amendments to California Exhaust Emission Standards and Test Procedures for 2004 Through 2026 Model Heavy-Duty Diesel Engines and Vehicles
Appendix B-1-1:  ~(accessible Word version)~
Appendix B-2: Proposed Amendments to California Exhaust Emission Standards and Test Procedures for 2004 Through 2026 Model Heavy-Duty Otto-Cycle Engines and Vehicles
Appendix B-2-1:  ~(accessible Word version)~
Appendix B-3: Proposed New California Exhaust Emission Standards and Test Procedures for 2027 and Subsequent Model Heavy-Duty Engines, Vehicles and Hybrid Powertrains
Appendix B-3-1:  ~(accessible Word version)~
Appendix B-4: Proposed Amendments to California Exhaust Emission Standards and Test Procedures for 2004 and Subsequent Model Heavy-Duty Diesel Engines and Vehicles, amended October 21, 2014
Appendix B-4-1:  ~(accessible Word version)~
Appendix B-5: Proposed Amendments to California Exhaust Emission Standards and Test Procedures for 2004 and Subsequent Model Heavy-Duty Otto-Cycle Engines and Vehicles, amended October 21, 2014
Appendix B-5-1:  ~(accessible Word version)~
Appendix B-6: California Evaporative Emission Standards and Test Procedures for 2001 and Subsequent Model Motor Vehicles, amended December 6, 2012
Appendix B-7: California Test Procedures for Evaluating Substitute Fuels and New Clean Fuels in 2015 and Subsequent Years, adopted March 22, 2012
Appendix B-8: California 2015 and Subsequent Model Criteria Pollutant Exhaust Emission Standards and Test Procedures and 2017 and Subsequent Model Greenhouse Gas Exhaust Emission Standards and Test Procedures for Passenger Cars, Light-Duty Trucks, and Medium-Duty Vehicles, amended December 6, 2012
Appendix B-9: California Exhaust Emission Standards and Test Procedures for 2018 and Subsequent Model Zero-Emission Vehicles and Hybrid Electric Vehicles, in the Passenger Car, Light-Duty Truck and Medium-Duty Vehicle Classes, amended September 3, 2015
Appendix B-10: California Refueling Emission Standards and Test Procedures for 2001 and Subsequent Model Motor Vehicles, amended March 22, 2012
Appendix B-11: California Non-Methane Organic Gas Test Procedures for 2017 and Subsequent Model Year Vehicles, adopted September 2, 2015
Appendix B-12: California Greenhouse Gas Exhaust Emission Standards and Test Procedures for 2014 and Subsequent Model Heavy-Duty Vehicles, adopted October 21, 2014
Appendix B-13: California Interim Certification Procedures For 2004 and Subsequent Model Hybrid-Electric and Other Hybrid Vehicles in the Urban Bus and Heavy-Duty Vehicle Classes, amended October 21, 2014
Appendix B-14: California Non-Methane Organic Gas Test Procedures for 1993 Through 2016 Model Year Vehicles, amended September 2, 2015
Appendix C-A-1: Purpose and Rationale for Proposed Amendments to Title 13 Regulation Order for Omnibus
Appendix C-A-2: Purpose and Rationale for Proposed New Section to Title 13 Regulation Order for Omnibus
Appendix C-B-1: Purpose and Rationale for Proposed Amendments to the Heavy-Duty Diesel Engine Test Procedures: California Exhaust Emission Standards and Test Procedures for 2004 Through 2026 Model Heavy-Duty Diesel Engines and Vehicles
Appendix C-B-2: Purpose and Rationale for Proposed Amendments to the Heavy-Duty Otto Cycle Engine Test Procedures: California Exhaust Emission Standards and Test Procedures for 2004 Through 2026 Model Heavy-Duty Otto-Cycle Engines and Vehicles
Appendix C-B-3: Purpose and Rationale for Proposed New Heavy-Duty Engine Test Procedures: California Exhaust Emission Standards and Test Procedures for 2027 and Subsequent Model Heavy-Duty Engines, Vehicles and Hybrid Powertrains
Appendix D: Costs and Economic Impacts Assessment
Appendix E: Emissions Inventory Methods and Results
Appendix F: Supplement to Initial Statement of Reasons – Proposed Low Carbon Fuel Standard Amendments (includes Purpose and Rationale for Proposed Amendments to the Low Carbon Fuel Standard Regulation)
Appendix G: Supplement to Initial Statement of Reasons – Proposed Emergency Vehicle Emissions Regulations