[Vwdiesel] Cheap crap oil

[Val Christian]

> Cheap crap, shouldn't be in your diesel in the first place, oil will only add 
> to the problem.

There is an interesting question here.  Has anyone seen peer reviewed 
papers on the down side of store-brand or other "cheap crap" oil?

Years ago I worked with a bunch of talented tribiologists (sp?) who
knew their oils, greases and additives.  This was back when I only
bought premium oils.  

I asked if they had any publications on the down side of low-cost
oils.  After some huffing and puffing, the red faced answer was that
they could only provide me peer-reviewed articles on the advantages 
of one additive over another, or the breakdown characteristics of one
base over another.

While they really knew their oils, the take-away I had was that even 
the "cheap crap" oils were quite adequate for most applications.  And 
even then, slightly more frequent changes would generally offset 
deficiencies.

Other take-aways I had were:

-multi vis oils are great, but VI agents are not good lubricators.  If
you want lubrication, use a straight weight oil, and pre-warm your 
sump.

-on an incremental dollar basis, spending an extra couple of dollars
per oil change on a better filter, was better insurance than spent
on an upgraded oil.

-as your engine gets older, and wear and blowby increase, more frequent 
oil changes, even with a lower cost oil are desirable.  Increasing the 
viscosity can help with seal losses.

-using heavy weight oils in an engine such as a diesel rabbit, while 
desirable from drain-down and bearing lube, can be adverse to rings.
They tend to carbon-up with heavier weight oil.  For cylinders, 5 weight
oil is quite sufficient. 5W-30 is quite fine in the winter.  (Just to 
prove I'm stubborn, I still use 20W50 and staright 40 oil in the summer.)

-oil selection is a compromise.  

I'd really be interested in qualified analysis of engine life using 
different cost oils.  We've all seen the engines idling at shows, 
using only some oil treatment as their lube.  Works fine at idle, and
with loose tolerances.  But how does real "cheap crap" oil fare?

Val