Thanks & appreciation for the info.  I've been quite happy changing my oil
and main filter religiously every 3000 miles/3 months for the past 35+ years
on all my VWs and since I haven't been into diesels since 1989, I'll just
keep moving along.....:-)
--
Jim Thompson
84 GL 1.9 "Gloria"
84 Westfalia 2.1 "Ole Putt"
72 411 Station Wagon "Pug"
oldvolkshome@gmail.com
http://www.oldvolkshome.com
***********************************
On Mon, Sep 28, 2009 at 10:47 AM, Michael Snow <slowmachine82@gmail.com>wrote:

> On Mon, Sep 28, 2009 at 12:18 PM, Old Volks Home <oldvolkshome@gmail.com>
> wrote:
> > And why would anyone use a bypass oil filter when both air and waterboxer
> > Vanagons have full-flow oil filtration?  Just curious......
>
> Using a bypass filter in addition to the full-flow filter provides a
> way to filter much smaller particles from the oil.  The stock filter
> is a compromise; it filters poorly enough to enable sufficient flow to
> the bearings and has a bypass valve that permits oil to flow around
> the filter media when flow is insufficient for proper lubrication.
> Much finer filters are available that will not flow sufficient oil for
> bearing lubrication.  Combining the two systems enables very fine
> filtration with sufficient flow for the bearings.  I won't say
> anything about the cost-effectiveness, only that it is possible to
> filter much more of the fine particulates from the engine oil than the
> stock system can support.
>
> --
> Michael Snow
> 1982 Westfalia 1.9TD
> http://slowmachine82.blogspot.com/