I was checking back and could not find any threads about air filters... just got the truck back from turbo cleaning, and dealer wanted to change air filter for $35. 00... If the K and N filter is an option now would be the time to purchase. Can't remember if this filter was a no-no on diesels. . I have one on every car in the family and have never been disappointed. If anyone has comments or is running one please post your thoughts... thank you!