My setup is not a true "cold" air intake since it draws air from inside the engine compartment and not cooler outside air by means of a scoop or inlet. It does, however, provide a huge increase in airflow over the factory setup which must draw all its air through this tiny inlet:
After I installed the system, my milage increased from 11-12 mpg to 15 mpg. Only 3-4 mpg, but still over 20% increase. I don't know if it gets the whole 11 horsepower gain that K&N claims, but there was a noticeable increase in throttle response and power. I should also add that I did my exhaust upgrade the same day so I don't know for sure how much of the improvements came from which modification.
Good luck with your project and, of course, Welcome to BroncoZone! >