If you don't replace your cabin air filter, you could be putting yourself and your passengers at risk. Dirty or clogged cabin air filters will reduce the amount of air flowing through the vents, leading to poor air quality and a range of other issues. Allergens, diesel fumes, and burnt oil can all enter the cabin without being filtered, and the filter will become increasingly clogged with dirt and debris. This can compromise the efficiency of your car's filter and HVAC system, leading to bad odors in the interior of the car and a decrease in air volume.
If you find yourself driving in heavily polluted areas or traveling on dirt roads, you should change your cabin air filter every 5,000 miles. This is likely because they don't understand the real dangers of not replacing it, partly because of the way cabin air filters have been marketed. Just because a cabin air filter doesn't directly affect your vehicle's movement from point A to point B doesn't mean you should delay buying a new one or not replacing it at all. Simply changing the cabin air filter will dramatically improve your vehicle's air quality.
But if you skip replacing your cabin air filter, you could end up spending thousands of dollars on repairs to your entire heating and air conditioning system. Because of its location, changing a cabin air filter is a difficult do-it-yourself project, so it's usually best to have it repaired by a trained mechanic. When updating your car's maintenance records, you'll see that replacing the cabin air filter is recommended. But what about hazards that can't be seen and effects that are only noticed gradually or during certain modes of operation? The reality is that a foul-smelling cab isn't the most pressing problem drivers will face if they never change the cabin air filter or if they don't change it often enough.
