K & N Air Filters
I e-mailed K&N and their product development team replied that a filter IS NOT availabe for the 2004 5.4L F-150. The link I provided in my previous post will get you on a notification list when the filter is available.
I had a K&N on my 1998 F150 w/ 4.6. I gained about 1 mpg in city and hwy driving (documented). With my current 2001 w/5.4 I did not gain much mpg at all.
My guess is that the 4.6 is much more air restrictive than the 5.4.
My guess is that the 4.6 is much more air restrictive than the 5.4.


