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Diesel Emissions Requirements

Diesel Emissions Requirements

Boulder County requires that diesel vehicles pass an emissions test in order to be registered. Details about requirements and exemptions are listed below as well as on the state’s Diesel Emissions Program page.

Test Locations

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

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 typically posted electronically to registration records within 2-3 days.
  • Once your passing emissions test has been posted electronically, you can renew your registration online or at a MV Express kiosk.

2020 Diesel Emissions Exemptions

The following diesel vehicles are exempt from emissions requirements:

  • Gross Vehicle Weight Rating (GVWR) up to 26,000 pounds:
    • Vehicles within the first four model years (In 2020, this means vehicles that are 2017 or newer are exempt.)
      • Exception: If vehicle ownership is being transferred in the last year of the four-year exemption, an emissions test will be required. (In 2020, this means that a 2017 vehicle will require an emissions test if there is a transfer of ownership.)
    • Vehicles 1975 and older with collector plates
    • Vehicles 1976 or newer that have been grandfathered (i.e. registered as a “collector’s item” prior to September 1, 2009 and registration has never lapsed/expired/or had a change of ownership)
  • Gross Vehicle Weight Rating (GVWR) 26,000 pounds or more:
    • Vehicles within the first six model years (In 2020, this means vehicles that are 2015 or newer are exempt.)
      • Exception: If vehicle ownership is being transferred in the last year of the six-year exemption, an emissions test will be required. (In 2020, this means that a 2015 vehicle will require an emissions test if there is a transfer of ownership.)
    • Vehicles 1975 and older with collector plates
    • Vehicles 1976 or newer that have been grandfathered (i.e. registered as a “collector’s item” prior to September 1, 2009 and registration has never lapsed/expired/or had a change of ownership)
  • If an exempt vehicle tests for emissions anytime during the exemption period, the exemption period is invalid and the vehicle must be tested every two years.

2020 Diesel Emissions Requirements

Unless the vehicle is exempt (see above), the following requirements apply:

  • Gross Vehicle Weight Rating (GVWR) up to 26,000 pounds require an emissions test starting in their fifth model year. (In 2020, this means vehicles that are 2016 or older require a test.)
    • 2011 and newer require an emissions test every two years.
    • 2010 and older require an emissions test annually.
    • 1976-1988 with collector plates require a test every 5 years.
  • Gross Vehicle Weight Rating (GVWR) 26,000 pounds or more require an emissions test starting in their seventh model year. (In 2020, this means vehicles that are 2014 or older require a test.)
    • 2012 and newer require an emissions test every two years.
    • 2011 and older require an emissions test annually.
    • 1976-1988 with collector plates require a test every 5 years.

Contact Us

Motor Vehicle Division

**New as of Jan 4, 2021**
7:30 a.m. – 5:00 p.m. Mon-Thurs.
CLOSED Fridays
Online Contact Form
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Phone: 303-413-7710

Fax: 303-413-7725 (Boulder office)
Fax: 303-413-7002 (Lafayette office)
Fax: 303-678-6126 (Longmont office)

Location

Boulder: 1750 33rd Street
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Longmont: 529 Coffman Street
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Lafayette: 1376 Miners Drive
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Mailing Address

1750 33rd Street, Suite 100
Boulder, CO 80301