I have a 2004 powerstroke with 44,000 miles, my question is how long does the air filter last ? The gauge on the filter box is only showing about halfway to the first line (25%) ? I just want to make sure I change it when needed and did not know how accurate the resriction gauge is...

Those gages are not accurate at all. I use my judgement and replace mine when in doubt.

Not accurate. 44k miles is about twice as long as you want to wait depending on condtions. Look at replaceing your system with a cold air intake....something with a dry filter....if you want. Diesels respond very well to opened up breathing.

Those little spring vacuum gauges don't work worth a damn in my opinion. They're all over the place depending on the weather and alignment of the stars.

Every 15K to 20K is a good time to change for mostly highway driving - if you do a lot of dirty off-roading, then it should be sooner.

I went with the TrueFlow foam filter replacement on my PSD; and love it. Its washable like the K&N, but filters better and flows better than K&N. I clean it every 15-20K miles.

For future reference; www.thedieselstop.com is the OSO of the PSD. K&N is quite strongly NOT recommended over there.

Thanks guys. I dont drive off road or in dusty conditions, just normal on road driving. I heard that ford said the filter was designed to go 100,000 miles in normal conditions ??? The factory filter is pretty expensive the best I remeber...

http://www.fleetfilter.com/Store_Vie...sel.asp?Cat=57
No way is it good for 100K miles. It's be chokin' by then.
$37 for a good WIX filter. It's what I use in mine. I change it about every 15K. Turbodiesels are very sensitive to airflow restriction, for mileage alone I'd change it often.

So the Wix filter is a direct replacement for the factory filter? Looks like I better be changing it soon, was just going by the restriction gauge is why I have not done it yet...

I use true flow CAI on my truck also, but its a gasser. Lots of cummins guys do the dry filter CAI on their trucks b/c the turbo seems to suck a think film of oil off the filter and onto the blades of the turbo.....dust and dirt then stick to it like glue. Have any issue with that on your ford?

I fortunately have not had to open my turbo housing, so unsure if I have a "glue" issue. However, I do not have any issues to speak of. (Knocking on wood; 85K miles and have been running the True-Flow since 60K miles.)