ive raced a stock explorer VS my explorer with just the K & N, and i got off the line quicker as well as beat him buy a good fender up to 70. Didnt really see a huge gain in MPG, i still sit at 16 no matter what, but the sound above 3K is great. Plus i got mine off someone esle that was selling their truck, so i got a good deal on it. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif The papers that came with it shows my exact truck getting a 7 horsepower gain with just the FIPK, but who knows how accurate/truthful that is.