In summary, K&N has been proven by 3rd party laboratory testing, with no payment or bribe money involved for "results", to pass more dirt, and not deliver enough benefits to cost/price/service time/oil contamination of your Mass Air Flow Sensor, as to be a liability instead of an asset.
You're being sold a placebo and a bill of goods that don't deliver. I won't tell you how to spend or save your money. Most OEM filter makers make filters for all kinds of applications andmediums/water/fluids/air.
K&N sells filters for nothing but boy toys with a motor on them. In terms of units sold, they are mouse nuts, and non existent in the OEM industry. There is a reason for that, probably has to do with the engineers that designed and built your motor knowing more about it's filtering needs than it's owner, that being you. Most of us consult an attorney when we need expertise in law, and accountant with our taxes, a doctor when we don't feel well. Consult the engineer that designed your motor before making filtering changes, if you want expert advice. Otherwise, leave it alone.