Most Cold Air Intake systems work in the same way they redirect the air intake for the engine to a cooler area usually in the front of the vehicle away form the heat of the motor. The Cold Air Intake will draw the air in and give it a straight shot to the intake manifold. This serves two main purposes; first the air will remain cooler and thus more dense and able to burn the fuel more efficiently and as a result giving your motor a few extra horsepower. Second the air is not subjected to all the twisting and redirecting as found in the stock air box so when it gets to your motor it is smooth and with out turbulence thus promoting a more efficient burn. Also Cold Air Intakes usually have a larger intake tube thus providing your motor with more air, more air = more horsepower!