Back in the olden days, pre smog equip, pre electronic fuel injection, when most cars had carberators, an oiled K&N filter was the way to go. I'm talking 1970's here. Today with the hypersensitive MAF's and sensors coming out the wazoo you are best going with a bone dry fine filter, like what came with the car.

What Jeff
 

Said, and you can take that to the bank

As said before i'm not sure why people still use these POS. They've been well documented on making a mess of throttle bodies, mafs and anything else in the line of that god awful oil they come with.
Then add in the fact that most of them live in the engine bay where they soak up hot air and you basically have a power sapping piece of junk.

The only thing they're fine on is old style out in the wind carbs and even then the likes of Pipercross make a better solution.