Test: K&N Cold Air Intake System

I've been looking for ways to improve my F-150 truck's fuel mileage. One of the things I'd considered was a cold air intake system, but the cost didn't justify the switch just for gas savings. Many people who've installed those systems say they use less gas, but a manufacturer's focus is on on how the units improve horsepower and torque. Aaron has been testing the K&N air filter over on the Cars Web site, and K&N sent me their Fuel Injection Performance Kit to try out. I installed it just before the homeward leg of a trip to the North Carolina coast. I'd hauled a trailer full of furniture over there and picked up a car on the return. I definitely felt an increase in power right away, and that's a great thing, but it's too soon to talk about fuel mileage. Let us know if you've used the system, or one similar to it, and what kind of results you had.