Mobile Source Emissions

We offer experience in all aspects of mobile source emissions regulation. For over two decades, the firm has engaged in a host of matters involving rulemakings, regulatory interpretation, compliance, enforcement, litigation, and advocacy with respect to automobiles and light-duty vehicles (gasoline, diesel, and electric), heavy-duty vehicles, non-road engines and equipment/vehicles, and commercial aircraft and marine engines.


  • Emissions standards
  • Vehicle testing and certification
  • Fuel economy requirements
  • Defeat device prohibition
  • Fleet compliance
  • Emissions warranties
  • Averaging/banking and trading provisions
  • Onboard diagnostics
  • Vehicle recalls
  • Exemptions
  • Import and export requirements
  • Engine and vehicle labeling
  • Electric vehicle and battery regulation
  • Federal Test Procedure dynamometer, in-use vehicle performance, and portable emissions monitoring system testing

The firm’s experience in the area of automotive regulation 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

  • Assisting Larry D. Thompson, former deputy U.S. attorney general, whom the U.S. government appointed as the Independent Corporate Compliance Monitor and Auditor for Volkswagen (VW), in one of the biggest environmental cases of the decade as part of VW’s criminal plea agreement stemming from the company’s scheme to sell diesel vehicles containing software designed to cheat on U.S. emissions tests.
  • 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.
  • 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.
  • Litigating preemption of state regulations under the CAA, “California” waivers, and emissions standards.
  • Working with the U.S. Environmental Protection Agency (EPA)'s Office of Transportation and Air Quality 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 the California Air Resources Board's Transition Program for Engine Manufacturers program.
  • Advising the Intelligent Transportation Society of America on climate regulation, emissions standards, and privacy issues.
  • 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.