Air filter

Used auto engine air filter, dirty side

 

Auto engine air filter clogged with dust and grime

An air filter is a device which removes solid particulates such as dust, pollen, mold, and bacteria from air. A clean Air Filter can increase your fuel economy. Dirty air filters can pass debris in to the Mass Air Flow (MAF) sensor and cause it to fail.

Automotive cabin air filters

The cabin air filter is typically a pleated-paper filter that is placed in the outside-air intake for the vehicle's passenger compartment. Some of these filters are rectangular and similar in shape to the combustion air filter. Others are uniquely shaped to fit the available space of particular vehicles' outside-air intakes. Being a relatively recent addition to automobile equipment, this filter is often overlooked. clogged or dirty cabin air filters can significantly reduce airflow from the cabin vents, as well as introduce allergens into the cabin air stream.

Internal combustion air filters

The combustion air filter prevents abrasive particulate matter from entering the engine's cylinders, where it would cause mechanical wear and oil contamination.
Most fuel injected vehicles use a pleated paper filter element in the form of a flat panel. This filter is usually placed inside a plastic box connected to the throttle body with an intake tube.

Older vehicles that use carburetors or throttle body fuel injection typically use a cylindrical air filter, usually a few inches high and between 6 and 16 inches in diameter. This is positioned above the carburetor or throttle body, usually in a metal or plastic container which may incorporate ducting to provide cool and/or warm inlet air, and secured with a metal or plastic lid.