Your vehicle’s engine relies on three things to be able to run – air, fuel, and spark. The air that enters the engine’s fuel system has to be clean and free of tiny particulates like grit, dust, pollen and sand. Were these particles to enter the engine, they would soon cause wear and damage.
Prior to the 1960s, engines used an oil bath filter where air would enter the system and be directed across a sump of oil; hopefully, particles would be trapped in the surface of the oil. Oil bath air filters were messy and inefficient and were replaced by a paper element filter in the early 60s. Paper air filters draw air past a pleated paper element, not unlike the intake filter in your home’s A/C system.
So how often does the filter need to be changed?