So a friend of mine bought a K&N air filter that supposedly has a lifetime warranty. It basically is a metal air filter which is washable and reusable with the help of some special oil. According to him he's getting about 2 to 3 mpg's more on his Jeep Cherokee, something to do with letting in more air with less dust particles... Would this filters benefit the HCH in any way? Does anyone own this air filter? I went to my local Walmart yesterday and they have the same air filter but made by another company... kinda look cheap though, the price on it wasn't, around 50 bucks.