Found this video. Not taking sides on any debate (I've already expressed my opinion), but I think this is worth watching. The roughly 2 % that they talk about at the end is essentially what I have witnessed.

 

Interesting clip Snoopy, and how did I know before I even clicked on it that there'd be a Skyline involved?

My opinions are pretty clear, any intake that's pulling in air from under the hood is a "Warm Air Intake", the stock intake on the HHR is a "Cold Air Intake" in that it draws air from outside the engine compartment.

But it should more properly be termed an "Ambient Air Intake" since that's the temperature of the air as it enters the system. These cone filter contraptions might look cool, but pulling the intake charge from right behind the radiator does defeat their supposed "CAI" advantages.

This should provoke some interesting debates back and forth.

 

I have been watching live data from my ECM lately. It is curious that even at highway speeds in 35F weather the Intake Air Temperature runs 20F higher than the Ambient Air Temp. That's all stock 2.2L. And the intake tube is wrapped in tape and firmly seated into the fender hole.

 

Should have figured on you collecting baseline data Don. As I've found, the GMPP intakes are averaging the same 20 degree +/- variation over ambient air temperatures.(not surprised by that in any way, I just installed them for the sound, and they do sound great)

It's something I expect, you do pick up some heat through the whooly worm, and radiant engine heat through the airbox.

What I'd like to do is get live data on an HHR with one of the supposed Cold Air Intakes, especially one hauling air in from behind the radiator.

 

I did add a cold air tube from the drivers side of the stock air box, all I noticed was lower fuel mileage and no noticeable increase in power so I went back to stock.