I just got done reading "Bobtheoilguy" site on Air filters. The net was that paper/fibre, like Baldwin & NAPA, as well as OEM, filtered better than K&N & Foam, with K&N showing maybe a little better. This was done over 500 miles, showing shades of dirt collected.
What are your thoughts on this? It seems to be shades of gray, with even the NAPA paper & K&N seeming near equal.
What that test does does include is real world experiene.
I like the K&N and from what I have read, it filters better the longer you use it, until it starts getting full, somewhere north of 50k.
I am not sure the test shows anything, except that all the filters allow some dust, some more than others.
Another conclusion is that a stock filter is fine for a stock motor. I believe the K&N's main value is that you never need to replace it, saving some money; also, maybe, some slight HP gain.
Opinions, experienece?
Intersted more in real life experience.

 

Using a K&N air filter on a turbocharged diesel engine in sometimes-severe conditions, i.e., where you might drive a pickup truck....

There are far better units that allow increased flow-through over paper filters, while actually filtering out contaminants. The AFE Proguard-7 is an example; there are others.

Want proof? Run a number of filters over the years in very dusty conditions, like I have. Wipe the intake blades of your turbocharger with a white tissue often. Nothing "grey" about it. K&N and other cheap, oiled filters not only let more dirt through, they wick more oil off the gauze and send it downstream to leave filmy residue over everything. The better oiled filters actually filter most of the dust, and retain the oil.

An old, old discussion - I'm sure someone's gonna disagree....

 

BOB has been on the net for a long time, People on the Porsche forum board whom are engineers and such trust him

 

Here is another interesting air filter test. It's done with the Duramax but I imagine results would be similar with the Cummins.

http://duramax-diesel.com/spicer/index.htm

 

The Silicon levels in my oil analyses are 3 to 5 PPM, with the stock air filter. Good enough for me...

 

Based un the Duramax test, The K&N certainly is a poor filter at Best. Seems stock, Baldwin, WIX are the best choices for most people. Anyone know who makes NAPA?
My K&N days are done.

 

I agree. Baldwin for fuel/oil and Amsoil dry air filter.
I think NAPA uses wix (primarily) but places their name on them. I know this is the same for CarQuest.

 

I ran a k&n on my chevy gasser before I knew better. On the CTD I'm using a S&B and have not seen any dust inside the tube.

 

My brother has run an oiled AFE air filter in his '06 cummins since new and his intake is completely dust free. We live in Northern Alberta, in the middle of farming country and dirt roads.

He's happy with his filter but I"m leaning towards a BHAF of some sort...when I finally get around to it. In the meantime, my stock replacement filter doesn't suck down the filter minder at all at 35 pounds of boost.