Smog & Emission Checks

Just because Montana does not require smog or emission checks on any vehicle, you should still keep yourself informed of the effects of pollutants and how you can help reduce the amount in our air.

How Vehicles Pollute the Air

Vehicle emissions are created when gasoline or diesel does not fully combust. Yet gas alone is not to blame for the pollutants that cloud our air. Emission controls, the design of your engine, and the improper care of your car are also culprits. Together, this combination leaves us with an atmosphere full of carbon monoxide, carbon dioxide, hydrocarbons, nitrogen oxides, sulfur oxides, and dangerous organic compounds. If that's not enough, this conglomeration of "secondary pollutants" create fine particulate (which increases the more our cars kick up dirt and dust) and ozone.

Cars are to blame for 75% of the carbon monoxide and 65% of the hydrocarbon that pollutes our air. The scary part is that more than half of this pollution comes from only 10% of the vehicles on the road. That's why it is so important to maintain your vehicle.

Tips for Keeping It Clean

• Even if your county does not require an emissions test, consider having one anyway to reduce pollution and get your car driving more miles per gallon.

• Consolidate the week's errands into fewer trips. This will save you time and money, as well as reduce the amount of emissions from your car if you narrow down the number of trips you take in your car.

• Spend hot summer days doing something other than refueling. During the heat of the day, ozone formation takes place. Therefore, refuel after 6 p.m. to keep smog-forming vapors out of the air.

• Listen for the first click of the gas pump when you are refueling, and stop pumping before you top off your tank. This will reduce the amount of smog-forming vapors emitted into the air.

• Tighten your gas cap until you hear it click, and you could be saving yourself from losing 30 gallons (due to evaporation) of gas per year and help keep our air a little more clean. In fact, 4,000 leaky caps alone create one ton of pollution.

• Turn off your engine if you know you'll be glued to the same spot for more than 30 seconds. Don't idle your vehicle unless you want to waste gas, pollute the air, and run the risk of damaging some engine parts.

For more information on the harm of emissions, how you can help reduce it, and how the government steps in to make a difference, visit the EPA's Office of Transportation and Air Quality.