Mobile Source Regulation

We offer experience in all aspects of mobile source regulation. For over two decades, the firm has engaged in 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, including small non-road mobile source 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

Our mobile source capabilities include counseling on 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, and electric vehicle and battery regulation. We also advise on Federal Test Procedure dynamometer, in-use verification program (IUVP) and in-use confirmatory program (IUCP), and portable emissions monitoring system (PEMS) testing.

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

  • 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 a variety of consent decrees and enforcement actions, including matters involving non-road small engine mobile sources.
  • Representing clients in criminal and civil enforcement actions under 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.
  • Resolving issues for alleged failures to comply with EPA and California Air Resources Board (CARB) requirements for obtaining Certificates of Conformity and Executive Orders.
  • Representing Original Equipment Manufacturers (OEMs) in matters related to Auxiliary Emission Control Device 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 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 CARB's Transition Program for Engine Manufacturers.
  • 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.