Originally Posted by 98CoupeV6

Dude your physics is all messed up.

Cold air is denser than warm air, so if you pull colder air into your engine it's the same as having a very slight turbocharging effect in warm air - that is, the air molecules are denser together.

However, when you're doing 75MPH, the air temperature a foot below your engine and above/next to your engine is going to be the same. "Cold air" intake is a misnomer.

Intakes gain power based on these things:
- The length of the tube versus stock. The length affects the turbulence of the air coming through the TB and manifold. More swirling is desired at low RPMs for torque and less is desired at higher RPMs for breathing. This is also called 'resonance length', and why an SRI will gain more horsepower/tq than a CAI on a 6gen Accord V6. It's also why SRIs dont lose torque down low (they're closer to the OEM length), whereas CAIs typically do.
- The breathability of the filter. Self explanatory, ANY aftermarket intake will have a better breathing filter than a stock filter resulting in power gains. However, more air = more fuel = more power = less fuel economy.
edit: - Also, the shape of the tubing, which affects the turbulence at the TB/IM and the speed at which the air is moving. CAIs have the advantage here because you can "straighten" the air flow out to achieve greater HP gains.