Other than electric cars, most modern automobile engines run by internal combustion and requires air to operate. That’s because without air, specifically, oxygen, fuels cannot burn to provide the explosive force that power the engine properly.
Have you ever found yourself in a situation where it was hard to breathe? It could because of a cold, allergies, smog or excess smoke in the air. How did it affect you? It probably slowed you down and took more effort to perform basic activities. A dirty air filter creates the same situation for your engine.
If the air going into the engine is not clean it runs the risk of dust, dirt and debris quickly fouling up the engine, causing poor performance and potentially shortening the life of the car.
Foreign particles in the air going into the engine act as abrasives, wearing away at engine bearings, piston rings and cylinders. In addition, modern engines rely on a precise ratio of air to fuel. When the engine is starved of air, the fuel mix is said to run too “rich,” which in effect puts added strain on the engine.