There are several kinds of filters in your engine, from those that deal with fluids like oil and fuel to those that treat the air. Without them, contaminants would easily infiltrate and harm various systems.
Your engine utilizes the air that comes in in two ways, either using it to assist with reducing heat or making it part of the combustion process that drives the pistons and makes your engine work in the first place. If dust, insects, bits of vegetation or any other contaminants carried along in the air made their way into the engine, they’d clog precision systems and cause expensive damage. The engine air filter ensures the clean air required for optimal engine performance.
In the cabin, the air filter is located behind the glove box and helps to keep allergens, dust, strong smells and other irritants from ruining your ride. You’ll want to change both filters every 15,000 miles or so to ensure clean air.