Cold Air Intake

A cold air intake is an aftermarket assembly of parts used to bring relatively cool air into a car's internal-combustion engine.

Most vehicles manufactured since the mid-1970s have thermostatic air intake systems that regulate the temperature of the air entering the engine's intake tract, providing warm air when the engine is cold and cold air when the engine is warm to maximize performance, efficiency, and fuel economy. Aftermarket cold air intake systems are marketed with claims of increased engine efficiency and performance. The putative principle behind a cold air intake is that cooler air has a higher density, thus containing more oxygen per volume unit than warmer air.