Smog & Emission Checks

The views when flying into the Salt Lake City airport or driving into the valley from the Wasatch Mountains can take your breath away―in a bad way. It's disconcerting to see the unpleasant brown haze you're about to inhale, particularly when there's an inversion layer. People living along Utah's Wasatch front are no strangers to stinging eyes and runny noses, but it's not hay fever they're suffering from. It's smog.

For such beautiful country, the Wasatch Front (the most populated region of the state) has suffered over the years from some pretty foul air; finally the state and federal governments set upper limits for allowable pollutants in Utah's environment. The state needs to meet these standards, so along with limiting pollution from such sources as factories, mines, and farms, the state has capped allowable emissions from automobiles as well.

Since 1984, Utahns in the densely populated Salt Lake, Davis, Utah, and Weber counties have taken their cars in for mandatory emissions testing every two years. Utah is unique in that it requires smog checks only in the counties that are the worse offenders, due to the number of cars they have on the road, rather than requiring these tests statewide.

Residents of these counties present a certificate of emissions inspection to the Utah Division of Motor Vehicles (DMV) when they register a motor vehicle or renew their registration.

The automobile emissions testing program contributes significantly to the state reaching its air quality goals each year. By repairing the 7% of cars (on average) that are shown by these tests to have excessive emissions, Utahns along the Wasatch Front enjoy cleaner air.

Emissions Inspection Requirements

To register a car in Salt Lake, Davis, Utah, or Weber county that is less than six years old, the vehicle is required to pass an emissions test every two years (if your car is brand new, you're exempt for your first two years. Motorcycles are also exempt). Cars with even-numbered model years will be tested every even-numbered year, and those with odd-numbered model years will be tested in odd-numbered years.

You won't need to remember this even/odd arrangement if your car is more than six years old because cars six years old and older (back to 1967) must have an emissions test every year. If your car's model year is 1967 or older, you're in the clear; emissions tests are not required.

You'll need to pass the emissions test no more than two months before your registration renewal. If your car fails the test, you are required to have it repaired, at your cost, so that it passes the test.

Inspection requirements in these counties may be different for diesel-powered vehicles; the DMV recommends that you call the local County Health Department for details:

• Davis County: (801) 546-8860

• Salt Lake County: (801) 313-6720

• Utah County: (801) 851-7600

• Weber County: (801) 399-7140

For information about residents of these counties buying cars from dealers outside the emissions testing area, visit the DMV's Vehicle Inspections page. Another helpful publication containing emissions information is the DMV's brochure, How to Register and Title Your Vehicle in Utah.

When You're Away

If you temporarily reside out of state (for example, if you are a college student or a member of the military), then you can keep your Utah registration up to date even if you can't get home to get an emissions test. You'll need to send in your registration renewal information and the proper fees along with an Exemption Affidavit of Utah Safety and Emission Requirements for Vehicles Not in Utah.

Note: You might still need to pass an emissions test for the state or county in which you reside. While living out of state, you are subject to the laws where you live. Refer to our Smog & Emission Checks section for the state in question to find out what its emissions-testing requirements are.

Report a Smoking Vehicle

While there is no statewide program that accepts complaints about polluting vehicles, if you happen to see a smoking vehicle in Salt Lake County, you can report it to the Salt Lake Valley Health Department.

Learn more about cleaning up our air at Utah Clean Cities, one of 85 coalitions in the United States working with the Department of Energy to reduce air pollution and dependence on foreign fuel sources.

Also see our Car Registration section for more general information.