FWIW, almost all oil filters have anti-drain back valves, and bypass valves as well.  It is the quality of the valve that matters (the cheap filters have plastic valves that are liable to break and or escape from their fastenings).   The oil filter review document discussed earlier mentions this matter.  BTW, the document does not review either Mann or Mehle filters, probably because they are not available for Fords.  DMc

---- Max Wellhouse <dimwittedmoose@CFU.NET> wrote:
> I seem to remember Dennis Haynes stating that the Mobil 1 filter for
> the Vanagon to be the cat's meow and superior to the Mahle while
> still having anti-drain back properties.  It was a couple of months
> ago for you archives freaks.
>
> DM&FS
>
> At 03:54 PM 10/31/2010, Bob Stevens wrote:
> >There is an "oil filter bible", much like the Oil Bible that gets passed
> >around
> >that is a very detailed study of ALL filters. The Fram was rated as one of
> >the least effective because of both the paper and # of folds used in them.
> >And yes, the Mahle spring tension for drain back resistance seems to be
> >the most effective.
> >
> >bob
> >
> >On Sun, Oct 31, 2010 at 12:33 PM, Don Hanson <dhanson928@gmail.com> wrote:
> >
> > >  I see the Mahle oil filter is what everyone says to use, but I have been
> > > using Fram or whatever I can get easily.  I have always changed my oil more
> > > frequently than most.  Until I swapped motors, only if my motor sat for a
> > > few days would my lifters click on start up....now they seem to click every
> > > time for perhaps 10 seconds or so...not so good, I imagine.  Is the Mahle
> > > filter supposed to help with this...some kinda drain-back valve in it or
> > > something?
> > >
> > >

--
David McNeely