Wondering about air filters? Check this site out. www.thedieselplace.com when you get into the site click on the "active topics" Then click on "Air Filter Study Complete" There you will find about 12 pages of very interesting reading. So grab a brew, sit back and enjoy.

 

I went there to check it out and was overwhelmed by the bazillion pages of stuff. I couldn't get past the first page, mostly because of time constraints. But Birch, if you've read all of that stuff and have some cool inside info on air filters, please let us in on it. I'm still messing around with the stock filters on our 2004 400's.