I have used the K&N induction system on my F250 SD (year 2000 7.3PSD) and thought nothing about it. I began research about 2 months ago and have dug up horror stories about these systems. Mine was, repeat was NOT a cold air intake and this in itself will reduce power. I then began a painstaking journey through the absolute hundreds of filters that can and can't filter air. I was amazed that AC Delco filtered the BEST for replacement paper. Then I found a MotorCraft product that has been out for some time and is manufactured by Donaldson's. The MotorCraft FA1759 (approved by Ford) AIS (air induction system) is a complete replacement package (replaces all the original box) and is considered the best extreme filtering system out there. The filters are spendy but last quite a while and NOTHING gets through. It is on my 7.3 now and it and myself breath a little better. It is a true dry filter cold air induction system.