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 Julio 21, 2026

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

This stage has not yet been reached. 

Hearing Action and Supplemental 15 Day Notices
Posted
Third Notice of Public Availability of Modified Text  (Deadline to Comment: August 5, 2026)
Appendix A-9.1  (Third 15-Day Changes Available for Comment)
Appendix A-9.2  ~Alternate Format to Appendix A-9.1~
Appendix A-9.3  ~For Review Only~
Appendix A-10.1  (Third 15-Day Changes Available for Comment)
Appendix A-10.2  ~Alternate Format to Appendix A-10.1~
Appendix A-10.3  ~For Review Only~
Posted
Second Notice of Public Availability of Modified Text and Availability of Additional Documents  (Deadline to Comment: July 15, 2026)
Appendix A-3.1  (Second 15-Day Changes Available for Comment)
Appendix A-3.2  ~Alternate Format to Appendix A-3.1~
Appendix A-3.3  ~For Review Only~
Appendix A-5.1  (Second 15-Day Changes Available for Comment)
Appendix A-5.2  ~Alternate Format to Appendix A-5.1~
Appendix A-5.3  ~For Review Only~
Appendix A-8.1  (Second 15-Day Changes Available for Comment)
Appendix A-8.2  ~Alternate Format to Appendix A-8.1~
Appendix A-8.3  ~For Review Only~

Additional Documents Added to the Record

In the interest of completeness and in accordance with Government Code section 11347.1, subdivision (a), staff has also added to the rulemaking record and invites comments on the following additional documents.

Posted
Notice of Public Availability of Modified Text and Availability of Additional Documents  (Deadline to Comment: April 20, 2026)
Appendix A-3.1  (15-Day Changes Available for Comment)
Appendix A-3.2  ~Alternate Format to Appendix A-3.1~
Appendix A-3.3  ~For Review Only~
Appendix A-4-1.1  (15-Day Changes Available for Comment)
Appendix A-4-1.2  ~Alternate Format to Appendix A-4-1.1~
Appendix A-4-1.3  ~For Review Only~
Appendix A-4-2.1  (15-Day Changes Available for Comment)
Appendix A-4-2.2  ~Alternate Format to Appendix A-4-2.1~
Appendix A-4-2.3  ~For Review Only~
Appendix A-5.1  (15-Day Changes Available for Comment)
Appendix A-5.2  ~Alternate Format to Appendix A-5.1~
Appendix A-5.3  ~For Review Only~
Appendix A-6.1  (15-Day Changes Available for Comment)
Appendix A-6.2  ~Alternate Format to Appendix A-6.1~
Appendix A-6.3  ~For Review Only~
Resolution 26-3

  Additional Documents Added to the Record

In the interest of completeness and in accordance with Government Code section 11347.1, subdivision (a), staff has also added to the rulemaking record and invites comments on the following additional documents.

Title 13, CCR, Section 1956.8.1

Title 13, CCR, Section 2423.0.1

Title 13, CCR, Section 2485.0.1

Public Hearing Notice and Related Material

Posted March 13, 2026

Notice of Rescheduled Public Hearing

Posted November 7, 2025

Notice of Postponement
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