California Air Resources Board (CARB) Rule


California's commitment to cleaner air is enhanced by the strict regulations set by the California Air Resources Board (CARB) for diesel vehicles.

California has stringent air quality regulations for diesel-powered trucks and buses. The regulations require that:

  • Diesel vehicles with a Gross Vehicle Weight Rating over 14,000 pounds must install particulate matter filters and upgrade their engines of the 2010 model year or newer to reduce exhaust emissions.
  • For heavier vehicles over 26,000 pounds GVWR, those from 1995-1999 needed to comply by January 1, 2020, while engines from 2000-2004 have until January 1, 2021.
  • Lighter vehicles, those with a GVWR between 14,001 and 26,000 pounds, have similar deadlines, with the oldest models (1995 and older) required to upgrade by January 1, 2015.
  • The regulations apply to a broad range of operators, including privately and federally owned vehicles, as well as vehicles operated by businesses, schools, tribal reservations, and government agencies in California.