Cold air intake (CAI)

A cold air intake, also sometimes called a cold air induction system, is something that looks similar to a car exhaust pipe, except that is fulfils the opposite role.

In very simple terms all normally aspirated auto engines mix fuel and air to create combustion in the cylinders of the engine. This explosive reaction causes the pistons to move which in turn powers a drive shaft that turns the vehicle’s wheels.

In most standard vehicles the air enters the engine when it is sucked through an air box, however this does have some drawbacks in terms of maximising engine performance. The main one being that the air that circulates around the engine is hot and this means that it has a lower density than an equivalent volume of much cooler air.

Given the fact that more air (denser air) generates a more powerful explosion and one that burns more of the fuel instantaneously, there is an obvious benefit in trying to get cold air into the engine and this is where a cold air intake (CAI) comes in.

What a CIA does is pull cold air from the front of the car (in front engine cars), e.g. typically from the space beyond the grill of the car and in front of the hot radiator. This results in cold air that has not come into contact with any part of the engine being pulled into the engine for maximum effect.

A CAI takes the form of a tube that normally runs from the back of the engine and around the side of the engine before finally exiting where there is a good flow of cool air. In high performance cars CAI are fitted as standard, however in most cars they are a performance enhancing mod that can be fitted with relative ease. If aesthetic and optimum performance are the goal then twin cold air intakes, where one runs either side of the engine body, offer the best benefits.