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    Smog Check Guide for Commercial Vehicles and Trucks

    truck exhaust smog

    To keep your vehicles safe, compliant, and on the road, chances are you’ll need to schedule them for a smog check periodically. Also known as a smog test or emissions test, smog checks must be performed at a licensed smog testing facility.

    If your fleet vehicles are not up to date or fail a test, you won’t be able to renew registrations. As a result, fleet managers must know about commercial truck smog checks and how to comply with them.

    What is a smog check?

    Cars and trucks are one of the leading causes of air pollution in America, so emissions standards play a major role in reducing damage. Smog checks were first introduced following the introduction of the Clean Air Act in 1966. Regulated by the Environmental Protection Agency (EPA), the goal is to protect public health and conserve the environment by improving air quality across the country. As fleet managers, it’s especially important to be compliant with smog regulations.

    The test is a thorough check of the vehicle, its tailpipe, and engine emissions to ensure compliance with regulations. It makes no difference whether the automobile in question is a car, taxi van, bus, lorry, or semi truck.

    Smog check procedures are the same for every vehicle type, including commercial vehicles like semi trucks. It is important to note that while the procedures are the same, smog check costs are usually higher for larger vehicles like commercial trucks.

    Which states require smog checks?

    Currently, 34 states require regular annual or biennial (every other year) emissions testing. However, regulations and rules are subject to frequent change, so we recommend you check with your state DMV or contact the Department of Transport directly to find the requirements relevant to your fleet.

    Each state follows its own protocols for testing, based on either federal or California standards. California is the only state with its own emissions standards, and they are the toughest in America. As a result, it is home to over 7,000 testing stations.

    Because many testing stations are privately owned, the price for smog checks is not regulated. So if you’ve been Googling away to find out ‘how much is a smog check?’ and come up with a bunch of different answers, this is one of the reasons why.

    We’ll go into smog check prices a little more later. But for now, let’s take a look at what the commercial truck smog check involves.

    What does a commercial truck smog check entail?

    A smog check includes inspection of a vehicle’s exhaust and pollution control systems. To receive a pass certificate, all parts and components must be up to standard. In a typical test, results are based on the following criteria:

    • Visual inspection - of all emission control components and systems.
    • Functional inspection - of the vehicle’s On-Board Diagnostic (OBD) system, check engine light, ignition timing, exhaust gas recirculation system, fuel evaporative system, and gas cap.
    • Emissions inspection – of tailpipe emissions.

    While you should expect all of the above to be included in the smog check price, California tests may involve additional assessments. After the test of your semi truck or commercial vehicle, you’ll get a Vehicle Inspection Report (VIR), and if all the criteria are met, you’ll be issued a certificate of compliance.

    Average smog check cost

    The average smog check price varies state by state, depending on the type of inspection. There is a case to be made that, due to more stringent criteria, California smog test costs may be higher. However, pricing policies mostly come down to the proprietor’s discretion and whether the testing station is state-licensed or privately owned.

    That said, two of our most frequently asked questions are ‘how much does a smog check cost in California?’, and more specifically, ‘how much does a smog check cost in Los Angeles/San Diego/ San Francisco?’, etc. With that in mind, we’ll stick with guideline prices that cover those questions.

    Smog check prices range between $30-$90. Fleet managers should expect to pay on the higher end of this range when getting a semi truck smog check. This is because larger vehicles require more time for the check to be completed. 

    As with many other states, California smog test costs only cover the main checks and VIR. They do not cover the State's Certificate Fee (currently $8.25). Some testing stations also charge an Electronic Transmission Fee (EFT) to cover the cost of transmitting your vehicle's information to the Bureau of Automotive Repairs (BAR) and the DMV.

    Smog check exemptions

    As with smog test costs, there may be some variance from state to state, although most pertain to the age of the vehicle and how it is powered. In California, exemptions include:

    • Gasoline-powered cars, motorcycles, and trailers manufactured in or before 1975.
    • Gasoline-powered vehicles less than 8 years old.
    • Any electric-powered vehicle.
    • Diesel-powered vehicles manufactured in or before 1997.
    • Diesel-powered vehicles with a Gross Vehicle Weight Rating of more than 14,000 pounds.
    • Natural gas-powered vehicles weighing more than 14,000 pounds.

    Need help managing your emissions?

    Fleet management software from Lytx helps you keep track of engine performance in all of your vehicles, improving safety and compliance across the board. Our preventative maintenance solution tracks the status of every vehicle, providing automated notifications that help you streamline your processes, reduce operational costs, and make preparing for smog checks a piece of cake.

    Contact us to learn more or book a demo, and start optimizing your commercial fleet today.