Subaru’s Most Neglected Maintenance Item Can Make You Sick

Forgetting it can make you sick.

Many new Subaru Crosstrek, Outback, Forester, and other model owners, and even those that have owned a Subaru for years, often forget about an important maintenance item. If you neglect to change it, it can pose serious health risks. It's the Subaru cabin air filter. 

The cabin air filter is an often overlooked maintenance item. It's out of sight and out of mind, and you only know it needs to be changed once it's too late.  

AutoZone says, "Not changing your cabin air filter can have serious consequences for your health and safety and that of your passengers. Most importantly, a dirty cabin air filter allows more harmful particles like odors, soot, smoke, and even exhaust fumes to enter the cabin – this can lead to negative health consequences for anyone traveling in your car."

That sounds scary.

Subaru says, "The cabin air filter plays a crucial role in ensuring you and your passengers breathe cleaner air by trapping dust, allergens, bacteria, and other small debris before it passes through the air vents in your Subaru." 

This should provide a sense of reassurance and safety to Subaru owners.

There's more 

That alone should be enough to convince Subaru owners to change the cabin air filter, but three more things are vital to know. 

1. A dirty filter puts more strain on the HVAC system. 

AutoZone says when that happens, parts like the heater fan and the blower motor resistor are susceptible to overheating from excessive use and can fail.

2. A dirty filter can cause your windshield to fog up. 

A dirty filter may cause your windshield to fog up, and the fan motor won't be able to clear because the vehicle's defroster isn't working at full capacity. Poor visibility could cause you to get in an accident. These types of collisions are completely avoidable with a minor maintenance item.

3. A dirty filter can decrease your fuel efficiency.

Surprisingly, if the cabin air filter is dirty, your fuel efficiency will decrease. Because the HVAC system needs more energy to push air into the cabin, it demands more power from the engine and takes more fuel to accommodate the loss of airflow. 

Knowing the importance of a cabin air filter, how it can affect your car's performance, and the symptoms a clogged cabin air filter can cause, it will be much easier to identify when you need a replacement.

Regularly changing your Subaru cabin air filter can help prevent these issues from happening in the first place.

How will you know if the cabin air filter is dirty?

AutoZone says to check if you need to replace your cabin air filter; start by inspecting the airflow from the vents in your vehicle and check for strange smells. That's the first step. 

Next, you can examine the cabin air filter. It's located behind the glove box. After you open the glove box, disconnect the damper by squeezing the stops on either side and pull them out. Lower the glove box and pull it out from the hinge. You can then remove the cabin air filter.

When to replace your cabin air filter

If you see dust, debris, bugs, or mold build up on the filter, replace it immediately. In most Subaru vehicles, this usually happens around every 12,000 miles.  

Checking your cabin air filter regularly and knowing when you need to replace it is vital to keeping your vehicle at peak performance.

Also, check out my report here on 5 Things You Should Never Do To Your Subaru.  

How much does a cabin air filter cost?

Replacing your cabin air filter doesn't take much time or require large sums of money. Most Subaru cabin air filters are less than $20. Once you understand the steps to perform this task, it becomes simple and cost-effective. 

Or, you can have Subaru change it for you.

If you don't want to change the filter yourself, the factory-trained technicians at your Subaru retailer will inspect the cabin air filter during your free multi-point inspection at each oil change service visit. 

If it's been a while since you've been in for service or if you've been driving in dusty, smoky, or city conditions, it might be time for a replacement air filter.

If you want the correct fit, get a Genuine Subaru Cabin Air Filter from your Subaru retailer. Replacing your cabin air filter is a simple yet essential task that should be regularly performed. It will improve fuel mileage, keep you cooler in the summer and warmer in the winter, and it could keep you from getting sick. 

I am Denis Flierl, a Senior Torque News Writer since 2012. I’ve invested over 13 years in the automotive industry in a consulting role, working with every major car brand. I am an experienced Rocky Mountain Automotive Press member. You'll find my expert Subaru analysis here. Follow me on my X SubaruReport, All Subaru, WRXSTI, @DenisFlierl, Facebook, and Instagram.

Photo credit: Subaru USA