Northern Front Range

As a single geographic ‘basin’ the entire Northern Front Range and Denver area suffers from elevated levels of ground level ozone air pollution. Ozone is a respiratory health hazard formed in the atmosphere by emissions from vehicles, industry, and oil and gas production. These emissions and the ozone they form are transported widely across this geographic area. Industry and the oil and gas businesses have made significant investments in emissions controls in recent years. This vehicle emissions testing program has been in place in the Denver area since 1995. Now it is time to for individual vehicles in Larimer and Weld counties to contribute to emissions reductions.

Because of the nature of our ozone problem and the technology on today’s vehicles, a higher tech test procedure involving varying vehicle loads and speeds is required. The testing equipment is very expensive and can only be economically employed in a dedicated high throughput inspection-only contractor setting. The test equipment is simply too expensive for most auto repair businesses to make a return on the investment.

Gasoline powered passenger cars and trucks after their fourth year of service from when they were new – all weights, all model years.

Proof of passing an emissions test must be submitted with vehicle registration renewal. In most cases this happens every other year. Your registration renewal postcard will state “Emissions Test Required”, meaning a test is required,; OR” No Emissions Test Required”, or “Passed Roadside Emissions”, in which case no action is required.

Once every two years for 1982 and newer model year vehicles. Every year for 1981 and older models. There is a four-year exemption for new vehicles.

All 1982 model year and newer vehicles are inspected every other year. Typically, vehicles of an even-numbered model year will be inspected in the even-numbered year, while odd-numbered model year vehicles are inspected in odd-numbered years. For example, a model year 1999 vehicle will need to be inspected prior to its registration renewal in 2011.

1981 and older model year vehicles are inspected every year.

Remember: If your registration renewal postcard says “Emissions Test Required”, you’ll need a test.

There are exceptions from emissions testing requirements, which include Farm-plated vehicles, Horseless carriage (pre 1942 models) vehicles, motorcycles and some collector series plated vehicles.

For a complete list of exempted vehicles go to About the Test: Exemptions

The emissions program for diesel powered vehicles is unchanged. Read More >

Emission testing will take place at a centralized, contractor-operated enhanced emissions testing center. There are four centers in Larimer and Weld Counties:

Fort Collins – 835 S.E. Frontage Rd, Ft. Collins, CO 80524
Greeley – 2844 W. 30th St., Greeley, CO 80631
Loveland - 7001 N. Franklin Ave, Loveland, CO 80538
Dacono-Firestone area – 5222 Silver Peak Ave., Dacono, CO 80514.

An emissions test costs $25. Cash or checks are accepted.

Vehicles that do not pass will need to be repaired and retested. There is no restriction on who can repair an emissions failure, but a list of suggested repair shops will be provided to you should your vehicle not pass.

One free after-repair emissions test is provided if it is performed within 10 calendar days of the initial test. After 10 days, or after a second test, the test fee is $25.

The I/M 240, for 1982 and newer model year vehicles, and a two-speed idle test for 1981 and older model year vehicles.

The I/M 240 test is a four-minute – 240 seconds – actual road simulation. The vehicle is placed on a treadmill-like device (called a dynamometer) that allows the vehicle to be tested under actual driving conditions. During the test emissions are collected from the tailpipe and analyzed. The idle test is shorter and does not require the dynamometer.

Yes, because of Original Equipment Manufacturer (OEM) design and/or safety considerations, some 1982 and newer vehicles are not tested on the dynamometer, but are instead tested with the two-speed idle test. For a list of exceptions to the IM240 dynamometer test, go to About the Test: I/M 240 Exemptions page.

Vehicles that are full-time four wheel drive, all-wheel drive or are equipped with disengagable traction control are tested using specially-designed dynamometers -- one set of rolls for the front wheels and an adjustable set (adjusted based on length of wheel base) under the rear wheels. Every station contains two lanes with two sets of all wheel drive dynamometer rolls, and the aforementioned vehicles are tested in these lanes. Vehicles that can be shifted from four-wheel drive to two-wheel drive must be tested on a two-wheel-drive dynamometer.

All Air Care Colorado inspectors spend two weeks in classroom training. They must pass exams to become certified inspectors. On-the-job shadowing is then conducted at stations for varying time periods. On-going training exercises and periodic refresher trainings are also part of the curriculum.

Air Care Colorado employs trained emissions testing specialists. They are not repair technicians or mechanics.

The Automobile Inspection and Readjustment Program is administered jointly by the Colorado Department of Public Health and Environment’s Air Pollution Control Division and the Colorado Department of Revenue’s Motor Vehicle Business Group.

The program is enforced by the County Clerks, acting in their role as motor vehicle registration agents.