Well I live in Phoenix arizona and I dyno'd my V6 Tiburon with AEMs short ram (which is a couple of brackets and a cone filter) and AEMs cold air. HP gains were the same at 3-5hp. In cooler climates cold air would be more beneficial and another thing to remember is it isnt just cooler air that makes better Hp its the fact that air is more dense the lower you are.

 

I had a CAI on my Accent and it worked pretty well. I got bored as I always do and made a short ram for it and ran a feeder tube to the fender-well. I then heat built a heat shield to block off the temp from the engine and especially the header. Throttle response is better, power has increased over the CAI by 2 horsepower.

 

How is cold air better then ram air. Ram air puts the air quickly into the engine and cold air taks a few seconds that will hurt you on the track.My friend has a 2000 honda si with a cold air and he payed over 300 dollar for a cold air intake and the filter got wet and full of dirt and couldnt be cleaned and it was ruined so he went for a ram air and he said he felt a faster accleration in his car