Mazda RX8 cold air intakes operate on the principle of increasing the amount of oxygen available for combustion with fuel. Because cooler air has more density for a given volume, cold air intakes generally work by introducing cooler air from outside the hot engine bay. However, the term "cold air intake" is often used to describe other methods of increasing oxygen to an engine, which may even increase the temperature of the air coming into an engine.

The Mazda RX8 Cold Air Intake is used to bring down the temperature of the air going into it's engine, which increases engine power. A secondary goal of the cold air intake may be to increase the visual appeal of the engine bay. It also slightly increases fuel economy, and can increase the life of the RX8 engine by allowing it to run cooler. Standard air intake systems tend to be restrictive, in order to save under-hood space and minimize noise in the cabin of the car. RX8 cold air intake systems come in many different colors and sizes, and are easy to install when compared with other performance-increasing modifications.

Some strategies used in designing RX8 cold air intakes are:

•   increasing the diameter of the air intake, allowing increased airflow.
•   smoothing the interior of the intake to reduce air resistance.
•   providing a more direct route to the air intake.
•   tuning the length of the intake to provide maximum airflow at certain engine speeds (RPM).
•   using a more efficient, less restricting air filter.

The company K&N Engineering first offered air intake systems in the late 1980s. Those intakes consisted of rotationally-molded plastic intake tubes and a conical, cotton gauze air filter. In the late 1990s a proliferation of intake manufacturers such as AEM, Airaid, Injen, True Flow, and Volant entered the fray.

In addition, overseas manufacturers imported their designs lending to the popularity of Japan domestic market air intakes like in the Mazda RX8. K&N and many of the other intake companies now offer intake systems in metal tube designs, allowing a greater degree of customization (the tubes can be powder-coated or painted to match a vehicle).