Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A cold air intake is a device used to bring lower temperature air into a car''s internal-combustion engine, to increase engine power and efficiency. Standard air intake systems tend to be very restrictive, in order to eliminate engine noise. Aftermarket cold air intake systems come in many different colors and sizes, and are easy to install when compared with other performance-increasing modifications. All cold air intakes operate on the principle of increasing the amount of oxygen available for combustion with fuel. Because cooler air has a higher density, cold air intakes generally work by introducing cooler air from outside the hot engine bay.