I don't believe you can get any noticeable improvement in MPG or POWER by using a K&N filter, but what you will get is more dirt in your engine. Look up some of the engine air filter tests online.Not so much noise, but if that's a side effect, I'll take it. I'm really looking to increase performance and mpg.
With a modern computer controlled ignition and fuel delivery system, even a fairly dirty air filter will barely reduce the mpg, but it can reduce the power somewhat under FULL throttle.
PSon't waster your money on those low priced 'Performance Chips' either, on a computer controlled ignition and fuel injection CRV.