What is a Smog Check? (2024)

The Drive and its partners may earn a commission if you purchase a product through one of our links. Read more.

People love to hang onto their classic cars for as long as possible, but the word “classic” has a different meaning to different people. Are we talking about a mint 1971 Olds 442, or are we talking about a 1995 Eagle Talon you found on Craigslist? Either way, you’ll want to make sure your car is able to pass whatever inspections your state throws at it.

One of the most common and important checks that states require is a smog test or check. They’re used to determine how much pollution your car returns to the Earth in the form of greenhouse gases and emissions from burning liquid dinosaurs. Each state is a little bit different, but the basic concept is the same: Make sure you’re not driving a poorly maintained rattletrap.

Smog checks are not that big of a deal, assuming you’ve kept up with your vehicle’s maintenance schedule and taken care of any physical damage that has occurred over the years. Having said all of that, you might be wondering what smog checks are, and what you’ll need to know to pass one. So follow along and let The Drive’s editors teach you everything you need to know. Let’s dig in.

Smog Check Basics: What is It?

California gets all of the attention when it comes to emissions laws and smog checks, but the reality is that several states have some version of the same vehicle inspection program. A smog check is a multi-part inspection that covers a vehicle’s exhaust and pollution control systems. In most cases, the process includes a visual inspection of the system and its components, a functional check to evaluate proper operation of the systems’ various parts, a check of the vehicle’s computer and diagnostics (on-board diagnostics, or OBD) systems, and a check to find out the level of emissions leaving a vehicle’s tailpipe.

How Much Does A Smog Check Cost?

In California, smog stations are DMV-authorized private businesses, which means that prices can vary quite a bit. In general, it’ll cost between $30 and $80 for a smog check. Other states may have different processes that cost more or less, depending on what’s involved.

It’s also worth noting that every state’s requirements are a little different. Some states perform a comprehensive inspection all at once that includes a check of other vehicle systems like brakes, steering, tires, and safety tech. Those inspections may cost more, because of their more in-depth process.

How Often Do I Need to Get a Smog Check?

Again, this will differ depending on where you live. California (do you like how we keep referencing the Golden State?) requires a check every two years. Other states, like parts of Maine, require a full inspection every year. Some don’t require a smog check at all.

It’s a good idea to stay on top of vehicle maintenance and take care of small problems before they become big ones. There’s almost nothing worse than pulling into an inspection, expecting to pay $30, and coming out with a hefty bill for a repair job.

Is The Smog Check Program Biased Against Older Vehicles?

In most places, no. Most programs have had exceptions built into the language of the laws that hold older vehicles to different standards than brand-new ones. Some states have antique vehicle designations that change the requirements for vehicles over a certain age, while others exempt older vehicles from the inspection process altogether.

What's The Difference Between Smog Check And Smog Test?

This will again depend on where you live, but stations that advertise only smog tests are only able to check your car to determine if it meets the requirements. Need a repair? You’re out of luck. Smog check stations are usually part of a larger vehicle maintenance and repair shop that can evaluate your vehicle and repair it as well.

Where Can I Get a Smog Check?

Depending on your state and area, you should be able to get a smog check at any franchise dealership (places with names like Smith Volkswagen, Johnson Ford, etc.), as well as a variety of individually-owned repair shops. Businesses that are certified to perform smog checks are usually quite happy to shout that out from the rooftops, so it shouldn’t be hard to find a reputable inspection shop.

Get Help With Checking Your Car’s Smog Test With JustAnswer

The Drive recognizes that while our How-To guides are detailed and easily followed, a rusty bolt, an engine component not in the correct position, or oil leaking everywhere can derail a project. That’s why we’ve partnered with JustAnswer, which connects you to certified mechanics around the globe, to get you through even the toughest jobs.

So if you have a question or are stuck, click here and talk to a mechanic near you.

Featured Products