A cold air intake gives a boost in performance to the engine of your vehicle. Air is one of those components necessary for combustion, but manufacturers of standard internal combustion engines pay only some attention to that fact -- actually, the standard air intake on most engines is designed for reduction of the noise from the required input of air and not for the improvement of the air flow to the combustion chamber.

The engine of your vehicle operates on a balance of fuel and air. The standard air intake tube does draw in enough air, but it allows the air to warm and expand as it passes through the noise-reducing twists and turns of the tube. The result is inefficient combustion. Cold air delivered in large volumes to the combustion chamber works to increase an engine's power efficiency by providing more oxygen in the denser air.

A cold air intake is both straighter and wider than a standard air intake -- more air is drawn in and the air spends less time being warmed. Placement of the air intake is another factor in engine efficiency. Standard placement of the air intake tube is within the vehicle's engine compartment, where the air is already hot. A cold air intake is placed to draw in air from a source outside the engine compartment, usually above one of the front tires in a wheel well.

The result is that every iota of power is pulled from every drop of ignited fuel. Combustion of fuel and warm air leaves unburned fuel in the exhaust. So, a cold air intake creates more power from the same amount of fuel. The next question, of course, is how much power is generated. Studies in engine monitoring have shown that a cold air intake can cause an increase of 5-10 horsepower in a standard engine. That result may be less or more for your engine, depending on the engine age and size, type of vehicle and any other performance improvements already installed. 

What this means for you and your driving experience is that you will feel the added power every time you step on the gas pedal. You'll get quicker response when the stoplight switches from red to green and when you're moving off the on-ramp onto a quick-paced highway. When you're passing a slower vehicle, you will really appreciate the extra punch you get to your speed.