Richard,the value of a K&N filter is in its airflow capabilitys,not filtration.I have oil samples from my truck,that told me to check my intake system,I had high silicon(dirt in the oil,after only 3K.I pulled the K&N,put the stocker back in and the levels are normal now.I have read on the turbo diesel register,that the $60 dollar filter for the Ram diesel has been passing to much dirt as well.I say run the stockers-its cheap and proven.I used to believe K&N filters were he best,and I ran them on everything that i had,even my ATV's.They do give more power,but at a cost.