I buy K&N's for my vehicles for the durability more so than any performance increases.  I'm not racing, I'm just a daily driver who wants to not have to replace an air filter EVER again.  These come PRE-OILED.  More than likely, unless you live in a very dusty environment, you'll NEVER need to clean the thing.  I read about people cleaning/oiling these things every --------miles.  NO NEED.  You're defeating one of the attributes of it...that being longevity.  Unless you can't see the mesh screening...leave it alone.  Also, IF you clean/recharge it, use the oil VERY sparingly.  For a panel filter such as this, a whopping 1.5 OUNCES is all you need.  Over oiling can lead to problems in the MAF sensor, as it lies directly downstream and can/will become coated if over-oiled causing driveability issues.