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Questions about oil

To: triumphs@autox.team.net
Subject: Questions about oil
From: Davgil@aol.com
Date: Thu, 14 Oct 1999 09:17:45 EDT
To the list

    There is an article in the November issue of Car and Driver by Patrick 
Bedard (page 23) about the right motor oil for "keeper cars" that I found 
very interesting and I would like to ask some of the real experts on LBC 
ownership about a couple of points.  In the article he states that "For our 
seldom-driven oldsters, (Ed) Kollin reckons that corrosion is a much bigger 
problem than wear, even the wear from starting an engine that's been sitting 
long enough to drain oil off most of its rubbing surfaces-because one little 
patch of rust on that same rubbing surface is doomsday".  I have always 
understood that the primary wear on an engine was during the initial startup 
until the oil was delivered to the critical components, I never thought about 
the effect of corrosion on those components.  When questioned about the best 
oil for an older, seldom driven car he later stated in the article "…for an 
off-the-shelf blend, he would choose a "heavy duty" oil intended for diesel 
trucks.  Instead of SJ (Spark Ignition) on the can, look for combinations 
that begin with C (Compression Ignition).  CG-4 is the latest, preceded by 
CF-4, CF-2, CF, etc.  A few blends meet both C and S requirements.  While the 
oil part of these diesel oils has the same lubricating qualities as 
passenger-car oil, the most common heavy duty viscosity is 15W-40; more 
syrupy.  But the diesels get bigger doses of the additives; up to 80 percent 
more ZDDP, and 30 to 50 percent more detergent, dispersant, and corrosion 
inhibitors".  In the article he states that ZDDP is the primary anti-wear and 
anti-oxidaton additive but it is used in smaller quantities in regular 
passenger car oil because it has an adverse effect on the catalytic converter 
which I assume is not a concern for our cars.

He goes on to state that the negative for using this type of oil is that the 
nitrogen compounds in the high does of dispersant may cause some seals to 
leak and that if you have not used a detergent oil before, you could wash 
loose a chunk of sludge that could clog a hydraulic lifter.  His comment was 
that heavy-duty oil was the silver bullet solution for corrosion as it is 
blended to neutralize the sulfuric acid produced by high-sulfur diesel fuel.  
My questions are these:

1. Does anyone on the list have experience with using this oil instead of 
regular passenger car oil?
2. Is there sufficient concern for the additional leaking seals (on an LBC 
-yeah right) to steer away from this oil?
3. Other than the cautions mentioned above, can anyone think of any other 
concerns to guard against?

Since I am a true rookie, I would appreciate the thoughts of some of the more 
knowledgeable list members.  As an aside to Joe Curry, maybe fluif has a 
diesel application.  TIA

David Gill
'76 TR6

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