Yep. The aftermarket floods the interweb with ads that boost "up to 12 HP gains" with a CAI. This was most likely true for applications such as a carbed engine, where it sat on top of the engine, and drew in hot engine heat. Then a brain engineer came along and created cowl induction; the engine was able to draw cooler air from the windshield area into the air cleaner.
With the modern engines, they moved the air intake to the front grill area to draw cooler air into the intake. The engineers have this right on 99% of stock to mild upgraded engines. Leave it that way unless you plan some sort of induction system, such as a turbo, or supercharger. This means you'll also be upgrading the exhaust (more air in requires the spent exhaust to get out quicker), plus a tune to re-adjust the fuel/air mixture and timing. All three of these will compliment each other.
If it's that "roar" your after, then remove the "muffler" type system that most stock air boxes have. Some have a square box along side the tube that runs from the air cleaner box to the intake. Others, like the Rangers, use a cone thats located in the air filter box. There's a write-upand Youtube on this forum or one of the others that show this simple mod. Or, if its eye candy your after, then its hard to beat a CAI with a off color air tube, and a nice pink/red/blue air filter.
Me? I've left everything the way it is. My 3.0 equipped Ranger was not intentionally built to set speed records. With 216K on its odometer, I think the Ford engineers got itn all just right the way it is.
If I want some weekend excitement, I hop into my 2011 Mustang!