Difference between cold air intake and regular air intake?

[skinz]

What's the difference?

 

[Bronco638]

A CAI gets it's air from outside the engine compartment.

I sent a note to KKM asking about this. Below is their response from their FAQ section:

Q: Why is the True-Rev Induction system not labeled as a cold air kit?
A: Our Testing has shown underhood air temperatures when driving down the road to be a few degrees warmer than outside air . With these results, we do not feel it is necessary to put restrictions on incoming air to the filter, by placing costly shields or ducting in our induction systems which would cause more restrictions.

Basically, the underhood area is not a hot still air chamber. When driving down the road there is quite a bit of airflow under the hood area.

 

[DeRocha]

I'm with Bronco... The basic difference obviously is a slightly colder air temperature reaching the intake manifold with a cold air system. A cold air intake will generally route outside air directly to the filter; while a regular intake will get air from "Under the hood air". Under the hood air is generally hotter and thus will yield slightly less power than denser colder air. From the various posts I've read it appears intake temperatures (air temp in the tube) for a cold air intake vs std intake closely match once the vehicle is moving; as such the performance gains would be minimal if at all.