Your Lungs Will Thank You! The Cabin Air Filter Cheat Sheet

Cabin air filter
K&N Reusable Cabin Air Filter| Micah Wright/Autos Cheat Sheet

Have you ever gotten into someone else’s car, and the first thing you notice is how the AC blowing out of the vent in front of your face smells like complete ass? Not to sound like a bunch of raging olfactory-obsessed snobs, but this has to be one of the most uncomfortable moments imaginable, as you sit there, politely pretending to listen to your friend or family member’s every word, as dust and mildew pummel your nostrils. Fortunately for us, this is a scenario that can be easily avoided with a dash of simple, and relatively inexpensive maintenance.

For all their practicality, cabin air filters are still a somewhat newer addition to the automobile, unlike the engine’s air filter, which has seen widespread use since the early 1900s. When automakers realized that tractors and military vehicles weren’t “shitting the bed” quite as often as common cars they looked into it, and found filters were the cause for success. Nevertheless, it was over half a century before drivers received a filter for exclusively for their cabins. While history professors and doctors would have us believe that smoking killed more Americans than Hitler, Lucky Strike wasn’t the only one left swinging the sickle. A deadly trifecta of second-hand tailpipe excretions, having drum brakes on all four hubs, and a complete lack of seat belts have all taken more lives than the National Highway Traffic Safety Administration would care to count.

Cabin air filter
Glove Box | Micah Wright/Autos Cheat Sheet

But it’s the first of the three that was changed forever in the late 1980s, when the implementation of cabin air filters began to gather steam in Europe, and a funky (and now defunct) Swedish company called Saab began offering an optional “particle filter” on 1987 models. Revolutionary at the time, these simplistic filters did little more than restrict cabin air flow and offer a splash of particle collection compared to today’s offerings, and according to German-based air filtration specialists Fiatec, Saab’s test conditions, methods, and product samples were often “hardly determined at all.”

Back then, cabin filters were designed to do little more than keep pollen and dust out of the interior of a car. While certain auto manufacturers like Mercedes-Benz followed suit with their own take on odor filtration in 1991, with the S-Class receiving nearly two pounds of activated carbon, it still wasn’t an ideal setup. Not to be outdone, in 1993 BMW outfitted its 7-Series sedans with the world’s first widely available combination cabin air filter, improving upon what Mercedes had started, but one-upping them by covering the AC side of things as well.

Here are a few key facts regarding cabin air filters that you should probably know:

  • After the first cabin filters were put into use in the late 1980s, an increase in public concern about air quality spawned the development of specialized media for the filtering of particles like diesel soot, sulfur dioxide, nitrous oxides, hydrogen sulfide, ammonia, and benzene derivatives.
  • European automakers then introduced absorptive systems, which were the great granddaddy of the modern day cabin filter, and even came complete with activated carbon.
  • Since their introduction, the cost of automotive cabin filters have dropped in cost by 75% across the board, thus making them easily obtainable and replaceable.
  • While a typical cabin air filter should be changed every 15,000 miles/every year, it’s important to remember that the service interval may also vary depending on one’s driving habits and environment. Always consult the maintenance section of your owner’s manual first to confirm the recommended service intervals for your vehicle.
  • According to independent tests conducted by filtration specialists Fram and cleaning gurus Arm & Hammer, the air inside your vehicle can be up to six times dirtier than the air outside. So you can see why we’re so adamant about upgrading your cabin’s air quality!
Cabin air filter
Dirty Cabin Air Filter | Micah Wright/Autos Cheat Sheet

Now that we’ve successfully convinced you that it might be about time to inspect your cabin air filter, it’s best for you to find out where the thing resides in your ride. But where on earth could it be? A quick search on the interweb should yield details on how to access and change the average cabin air filter, so type in your year/make/model and see what you find.

Chances are that your cabin air filter is tucked away somewhere behind the glovebox, in the cowl beneath the wiper arms, or underneath the dash, and to get to it, all you’re likely to need is a flashlight and a screwdriver. If you’re fortunate enough to have something like a first-generation Acura RDX, all you have to do is un-clip some plastic arms holding up the glovebox, lower the unit completely, and then pull on two tabs in order to remove the filter.

Car air filter
Washable K&N Filter | Micah Wright/Autos Cheat Sheet

Once the old filter is removed, take a good look at it. If it appears disgusting, then it’s probably time for a fresh one. Hell, even if it doesn’t look filthy at first glance, take a quick peek between the pleats and see what you find. Chances are you’ll discover all kinds of nastiness tucked away within those folds; so if you haven’t already secured a fresh filter, hop in your car (it will run just fine without a cabin air filter in it) and head down to your local auto parts store or shopping center. As long as you aren’t driving something like a Maserati, there will likely be two to three choices available for your vehicle, which leads us to the next question. Which filter should you get?

While most people opt for the cheapest option on the shelf, not all air filters are made equal, and while a $7 selection may sound like a great deal, going with a more media-rich product really is the way to go. Sure, if you’re selling your car or don’t suffer from allergies then don’t sweat the good stuff, but if you have kids, live on a dirt road, reside in a city with prolific air pollution, or are a hopeless germophobe, then there are some fantastic options out there worth considering. If a basic Wix filter is inexpensive and prevents bacterial growth, and a Fram FreshBreeze replacement costs more, but eliminates odors with activated carbon and baking soda, then going all-out and buying a top dollar K&N cabin air filter is the ultimate solution.

Long known for being the king of engine air filtration, K&N’s cabin offering is a completely washable and reusable product that cleans and freshens incoming air, and it comes right out of the box electrostatically charged to capture dust, odor, mold, mildew, pollen, spores, fungus, and germs. By utilizing a combination of metal mesh-wrapped, over-sized pleats, advanced synthetic filter media composites, and a sturdy silicone frame, K&N cabin air filters are able to boast a 10-year/100,000-mile limited warranty and more filtration than any other product on the market today. Sure, they cost about twice as much as your standard filter, but you won’t have to replace it for a decade, in the process saving you money, protecting the environment, and giving both driver and passenger alike cleaner cabin air.

Oh, and when that K&N cabin filter does get dirty, spend the $13 and buy a K&N cabin air filter cleaning kit to spray the filter with a biodegradable solvent that loosens dirt and road grime. Once the filter is rinsed clean, break-out the included Refresher spray to increase the electrostatic properties of the cabin air filter to better trap contaminants. You’ll have to wait for the filter to dry, but if you do this in the evening when you get home from work, by the next morning it’ll be dry and you can just pop it back in before hitting the road! It may not protect you from chemical warfare like the HEPA filter found in the Tesla Model X claims to cover, but it will still give you reason to breathe easier every time you turn the key.

  • Check out Autos Cheat Sheet on Facebook