In short, it is the filter that purifies the air we breathe inside the car. It has the same function as the air conditioning or furnace filters we use at home. Although over 220 million vehicles in the US (76% of registered vehicles) are equipped with cabin air filters, few are aware of its existence or functionality.
Currently, there is no consensus in the automotive industry regarding a standardized product name. Car manufacturers, in owner’s manuals, use various terms to reference the SAME filter type. BMW refers to it as either as “microfilter,” or as an “activated charcoal filter.” Honda and Acura refer to it as a “dust and pollen filter.” Toyota and Lexus refer to it as an “air conditioning filter.” Jeep, Ram, Chrysler, Dodge, Ford and Lincoln refer to it as a “cabin air filter.” GM (Cadillac, Chevrolet, Buick) refers to it as a “passenger compartment air Filter.” Hyundai and Kia use both terms interchangeably “cabin air filter” and “climate control air filter.” Volvo refers to it as a “passenger compartment air filter.” While others also refer to it as an HVAC filter, ventilation filter, and/or AC filter.
When Were Cabin Air Filters First Introduced?
According to Motor Magazine, “the first known OE cabin air filter was used on a Rambler in the 1970s.” However, Rambler was sold only in limited International markets outside the U.S., when, in reality, Saab was the first OEM to widely introduce a cabin air filter as a standard feature in all of its models, starting in 1979 with its 900 model. “BMW, Mazda and Ford Europe incorporated cabin air filtration in the late 1980s, while Volvo debuted cabin air filtration in 1993.” In the U.S., “the 1995 Ford Contour and Mercury Mystique compacts were the first domestic nameplates equipped with cabin air filters.”
What does a cabin air filter do?

Often consumers confuse the engine air filter with the cabin air filter. While the former is to protect the engine, the latter protects the driver and passenger by ensuring the quality of air they breathe inside the car.
Engine air filter cleans the air before it enters the combustion chamber in the engine, where flow rate is critical, to ensure optimal performance and fuel economy. It is mostly designed to remove dust particles larger than 3 microns. Cabin air filters protect the driver and passenger by eliminating fine dust as small as 0.3 microns.
Some cabin filters include a layer of activated charcoal to remove harmful gases like carbon monoxide and sulfur-dioxide. More advanced technologies for cabin air filtration, like PureFlow, combine these technologies, with a layer of backing soda and high-tech nano silver and nano copper particles. These filters have the ability to weaken, or deactivate, viruses, germs and bacteria, while also eliminating odors and undesired smells.
What is the Best Cabin Filter For My Car?
Finding the filter that fits your car is easy: simply search the year, make and model of your car Search.
While there are many choices, it is important to understand that, although all filters look similar, the results can greatly vary. Premium filters like PureFlow offer a higher efficiency in capturing fine dust, as well as coarse dust (10 microns or larger), while economy filters primarily filter out large particles. So, it is critical to verify the performance in the filter.
While the MERV rating is the most common rating for home air filters, in the automotive industry, the common scale is based on the ISO-55111 testing protocol, where quality cabin filters are expected to eliminate over 90% of fine dust and over 99% of coarse dust.
How Often Should I Replace the Cabin Filter?
Just like your air filter at home, cabin filters for cars should be replaced once or twice a year. There are several factors that can impact the performance of the cabin air filters; dust, road grime, leaves and other particulate matter clogs the filter and slows air flow. Humidity and moisture can be another factor that can impact the performance of your filter. In fact, anytime you feel that the flow of air inside your car is being disrupted or weakened, that means it’s time to replace your cabin filter. Some would prefer to replace the filter after pollen season and ahead of the hot summer to ensure the flow of cold air, or after fall and before winter, when the dry leaves and debris seasons are over, to ensure the flow of hot air in the winter. Others prefer to replace the filter ahead of allergy season. This is not a mechanical car question, but a judgment call that drivers and passengers need to make any time the flow of air inside the car is weakened or musty smell is detected.
Continue reading our other articles to find the right filter for your cabin interior so that your air is always fresh.