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From: pwv@fluke.UUCP (Pat Vilbrandt)
Newsgroups: net.auto
Subject: Re: Mobil One recommendations?
Message-ID: <747@vax1.fluke.UUCP>
Date: Wed, 3-Oct-84 14:24:54 EDT
Article-I.D.: vax1.747
Posted: Wed Oct  3 14:24:54 1984
Date-Received: Sat, 6-Oct-84 05:34:50 EDT
References: <166@maxvax.UUCP>
Organization: John Fluke Mfg. Co., Everett, WA
Lines: 74

[... slip-slide me some oil ...]
				-The Tin Man (Nipsy Russel)
				 "THE WIZ"

I, too, had many questions about synthetic oils and had heard many
(unsubstantiated) horror stories about their use, so I decided to try my own
(moderately) controlled experiment.  I bought a shiny new Subaru 4WD wagon in
Sept. of '77 and after the 1000 mi. check, ignoring the warranty warnings I
put Mobil 1 synthetic oil in the crankcase.  Thereafter, I changed the oil
filter every 4-5K mi. and changed the oil every 25K mi.  (I drive about 40
mi./day, mainly highway.)  The oil consumption has been one quart every 1.5-2K
mi. (mostly up the PCV hoses, I think).

As for cost, at $3.95 (typ.) a quart, this schedule cost me about $0.0030/mi.
Comparing this to using, say Penzoil 10W40 (my next choice after Mobil 1) at
~$1.10/qt on a 5K mi. change schedule, the cost would be about $0.0016/mi.  So
the lubricant cost works out to about double.

The engine always performed well.  The only external effect of using the
synthetic was that the engine stayed relatively clean.  What little synthetic
oil leaked out of the engine didn't break down into sludge like petroleum
based lubricants do.  I theorized that this was true for the inside of the
engine as well.

After ~85K mi., as the result of engine block failure, I had the pleasant
opportunity of tearing the engine down and rebuilding it.  I was very
pleasantly surprised at the overall condition of the engine, except of course
for the problem that led me into the rebuild in the first place.  There were
almost no deposits or varnish at all in the engine.  Most importantly, close
inspection of the bearings, journals, wrist pins, rings, et. al. with
micrometers and calipers showed almost no discernible wear (most within the
normal to high side of the range for "new").  The only exception were the
thrust surfaces on the center main which showed about 0.003" of combined wear,
still well within the tolerance range (clearance limit 0.012"). 

For a 1600cc four banger driven relatively hard, I feel that the condition of
the engine warranted the additional expense of Mobil 1.

NOTE and WARNING to other Subaru owners of similar vintages:  The engine block
failure I speak of was caused by overheating (loss of coolant from water pump
seal failure while highway driving).  I didn't think the overheating was bad
since I noticed the temp. gauge was high before I lost all coolant and stopped
to add water which got me home.  However, the engine block design (steel
sleeves in an aluminum block) leaves the "bottoms" of the cylinders relatively
unsupported.  This overheating caused the bottoms of the cylinders to "sag"
and stretch so that they were about 0.005" to large and up to 0.008" out of
round.  (I say "bottoms", however, Subaru engines are a horizontally opposed
flat four, so it was really the "back" of the cylinder.)  This resulted, of
course, in compression loss and excessive oil burning at the bottom of the
stroke.  

I do not, in any way, relate this problem to lubricant failure, since there
was no cylinder scoring or wear.  The relatively "thin" Mobil 1 (rated 5W30)
appeared to have kept its film strength even when the engine overheated, for
what it's worth.  This is a distinct advantage of synthetics over regular
petroleum based oils, I feel.

So, after a 0.025" over rebore, new pistons and rings, the Sube is back on the
road with Mobil 1 and 99+K mi., and probably will go another 99+K (I watch the
coolant level religiously now).

DISCLAIMER:  

My experience has been with MOBIL 1, a 100% synthetic oil.  I have used no
other materials or additives.  I have had no experience with any other
synthetics.  I have no interest in Mobil Oil Co. or Subaru of America,
financial or otherwise.  This is only personal experience.  I make no
recommendations either pro or con for any of their products.  Nyah, Nyah,
Nyah.-- 

   Pat Vilbrandt
   John Fluke Mfg. Co., Inc.
   Everett, Washington USA
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