Some county buildings are reopening to the public on June 1, while other services remain online. See current safer-at-home order with face coverings.

Resources are available for those impacted by COVID-19. For help, submit questions or call 720-776-0822 weekdays (9 a.m.-5 p.m.).

Level 1 Fire Restrictions remain in place for western Boulder County. View the flyer and map for more details. No fires, no shooting.

Diesel Emissions Requirements

Diesel Emissions Requirements

Test Locations

Several testing locations are available for diesel vehicles. Diesel vehicles are not tested at Air Care Colorado.

Exemptions

Diesel vehicles are exempt from an emissions test within the first four years of service. For example:

  • In 2016, all 2013-2016 model-year diesel vehicles are exempt from an emissions test.
  • In 2017, all 2014-2017 model-year diesel vehicles are exempt from an emissions test.

If an exempt vehicle tests for emissions anytime during the four-year exemption period, the four-year exemption period is invalid and the vehicle must be tested every two years.

Light-Duty Vehicles

Light-duty vehicles have a gross vehicle weight rating (GVWR) of 14,000 pounds or less and must meet the following requirements:

  • Models that are under 11 years old require a diesel emissions test every other year. In 2020, this includes models that are 2011 or newer.
  • Models that are in their 11th year and beyond require a diesel emissions test every year. In 2020, this includes models that are 2010 or older.

Heavy-Duty Vehicles

Heavy-duty vehicles have a gross vehicle weight rating (GVWR) of 14,001 pounds or more and must meet the following requirements:

  • Vehicles in their fifth through tenth year of service require a diesel emissions test every other year.
  • Vehicles in their eleventh year of service require a diesel emissions test every year.

Effective August 5, 2015 heavy-duty vehicles with a gross vehicle weight rating (GVWR) of 26,000 pounds or more are exempt from emissions for the first 6 years. Six years is calculated by adding 6 years to the model year of the vehicle, for example a 2016 vehicle plus 6 years would require a test in 2022.

Registration Renewal

Obtain an emissions test if the statement “Emissions Test is Required” appears on the vehicle registration renewal notice.

  • Diesel emissions test results are not posted electronically to registration records.
  • Proof of the diesel emissions test must be submitted with payment.

Contact the Department of Revenue at 303-205-5603 for more diesel emissions information.

Contact Us

Motor Vehicle Division

303-413-7710
303-413-7725 (Fax)
Email
Hours: 8 a.m. – 4:30 p.m. M-F

Location

Boulder: 1750 33rd Street
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Longmont: 529 Coffman Street
Map & Directions

Lafayette: 1376 Miners Drive
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Mailing Address

1750 33rd Street, Suite 100
Boulder, CO 80301