Mobile Source Regulation

We offer experience in all aspects of U.S. EPA and California Air Resources Board (CARB) mobile source regulation and enforcement. For decades, the firm has engaged in matters involving rulemakings, regulatory interpretation, compliance, enforcement defense, litigation, and advocacy with respect to mobile sources. This includes providing counsel on issues relating to automobiles and light-duty vehicles (gasoline, diesel, and electric), heavy-duty vehicles, non-road mobile sources – including small non-road engines and equipment/vehicles – commercial aircraft, locomotives and marine engines, and electric vehicles.


  • Emissions standards

  • Vehicle testing and certification

  • Greenhouse gas regulation/ Fuel economy requirements

  • Defeat device prohibition

  • Fleet compliance

  • Emissions warranties

  • Averaging, banking, and trading (ABT) provisions

  • Onboard diagnostics (OBD)

  • Vehicle recalls and Defect Reporting

  • Import and export requirements and exemptions

  • Engine and vehicle labeling

  • Electric vehicle and battery regulation

  • Federal Test Procedure dynamometer, in-use vehicle performance (IUVP/ IUCP), and portable emissions monitoring system (PEMS) testing

  • “Kit Cars” and “Specialty Constructed Vehicles”

  • Federal Motor Vehicle Safety Standards

  • California LCFS Compliance

  • NHTSA Reporting and Compliance (TREAD Act, EWR)

  • Clean Air Act Preemption

  • Vehicle compliance programs, policies and auditing

  • Indirect Source Regulation

  • Vehicle Miles Traveled Regulatory Programs

  • On Road and Nonroad Engine/Vehicle Regulation

  • California and State Requirements

The firm’s automotive regulation experience also extends to European Union and Worldwide Harmonised Light Vehicle Test Procedure regulatory standards and requirements and, to a more limited extent, Chinese vehicle regulation.

Representative Matters

  • Representing major auto, heavy duty truck, and nonroad equipment manufacturers in a variety of U.S. EPA and CARB enforcement actions.

  • Negotiating consent decrees on behalf of Fortune 500 companies in U.S. DOJ enforcement cases.

  • Assisting Larry D. Thompson, former U.S. Deputy Attorney General, whom the U.S. government appointed as the Independent Compliance Monitor and Auditor for VW, in conjunction with VW’s criminal plea agreement and consent decree stemming from the company’s scheme to sell diesel vehicles containing software designed to cheat on U.S. emissions requirements.

  • Representing clients in criminal and civil enforcement actions under U.S. EPA’s aftermarket defeat device National Compliance Initiative.

  • Successfully challenging state regulation of air emissions on preemption grounds under Section 209 of the Clean Air Act (CAA).

  • Counseling automotive manufacturers on making self-disclosures to regulatory agencies about vehicle certification non-compliance issues.

  • Conducting OEM emissions compliance assessments and training programs

  • Favorably resolving alleged failures to comply with U.S. EPA and CARB requirements for obtaining Certificates of Conformity and Executive Orders.

  • Representing Original Equipment Manufacturers (OEMs) in matters related to Auxiliary Emission Control Device (AECD) reporting under CARB and EPA regulations and counseling on the scope of defeat device exceptions under applicable law.

  • Representing the trucking industry in the litigation and settlement of the Heavy Duty Diesel Engine Consent Decree that concerned the use of engine emissions defeat devices.

  • Litigation related to preemption of state regulation under the CAA, “California” waivers, and emissions standards.

  • Working with U.S. EPA's Office of Transportation and Air Quality (OTAQ) on the successful introduction and transition of on-road and non-road vehicles to successively more stringent tiers of vehicles emissions standards under EPA and CARB's Transition Program for Engine Manufacturers (TPEM).

  • Advising clients on climate regulation, carbon-related exhaust emissions (CREE) standards, and greenhouse gas (GHG) emissions credits.

  • Representing an automobile technician facing criminal CAA charges relating to allegations of falsifying vehicle emissions arising from a national enforcement initiative titled “Operation Clean Scan,” obtaining a favorable probationary sentence along with a minimal fine.