Often consumers confuse engine air filter with cabin air filter. While the former is to protect the engine, cabin filter protects the driver and passenger. 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.
Protecting the driver and passengers is a different task. Cabin filter are designed to eliminate find dust as small as 0.3 micron and others are also designed to remove harmful gases like carbon monoxide and sulfur-dioxide to name few. More advance technologies for cabin air filtration like PUREFLOW., have the ability to weaken or inactivate viruses, germs and bacteria. Such premium products have the capacity to eliminating odors and undesired smells.