Cold air intake or open air?

I am guessing the obvious answer is cold air, but then why dont I see this on most cars? Does anyone feel the difference between the 2?

/??

Edited: 12/15/2010 11:01:11 AM by truck action

Out here in Cali, you have to draw air from outside the engine bay for smog pass!A true cold air system ( like you show) is most functional & is what I run on my Toyota 22RE.

I'm not really sure..:)

Cold air systems really do work well if fitted properly.

cool air is better. i have a tube with a k&n on the end, its open air it and it works fine