Date: Sat, 3 Nov 2012 18:48:10 -0500
Reply-To: mcneely4@COX.NET
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dave Mcneely <mcneely4@COX.NET>
Subject: E
In-Reply-To: <169D280C-CF2E-49AF-AAEB-3D1DAE63B49F@eoni.com>
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Jim and others, my understanding is that the ZDDP concentration in modern oils is the same as it was in the 1950s (about 600 ppm), when it was introduced to protect the valve and tappet design then current. The concentration was increased later for a different reason, having to do with detergent properties of oil. Since catalytic converters have been required, the ZDDP concentration has been dropping to keep the converter functioning for 150k miles, but it is still adequate, with other changes in oil formulations, to protect the valves in older vehicles. In fact, if I am not mistaken, I got that information from the same GM author that your citation references.
I am stating this from memory, rather than from reviewing the original report I read right now, but I do think I am remembering correctly. The particular link you provided only gives data on oils, but the report I read (same author) discusses backwards compatibility of "star burst" oils (the modern service rated oils with the starburst symbol like), and the testing and results for oil service ratings
Basically, the report referred to the "myth" that the ZDDP levels in modern oils are too low to protect older engines.
Correct me if I am wrong. If so, I hope you will explain more completely than I have. mcneely
---- Jim Arnott <jrasite@EONI.COM> wrote:
> Jack,
>
> 5W40 Rotella T6 synthetic. That big Arkansas box store. $20/gal. And
> no.... the oil specified in the '84 owner's manual is no longer
> manufactured. As engines have moved away from a flat tappet design,
> manufacturers have changed the oil specifications. Typically removing
> the zinc (ZDDP) necessary for reduced cam wear in our engines. Diesel
> spec oils have the maximum in currently produced lubricating oil.
> Rotella T6 synthetic has the highest concentration of all current mass-
> produced motor oils.
>
> < http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2330040#Post2330040
> >
>
> Jim
>
>
> Kindness in words creates confidence. Kindness in thinking creates
> profoundness. Kindness in giving creates love.
> --Lao Tzu
>
> On Nov 2, 2012, at 9:27 PM, Rocket J Squirrel wrote:
>
> > I'll need to bust out the owner's manual to see what they recommend
> > for
> > the Cold Season. Nights down to mid-teens (F), days up to 40s. Is this
> > ca. 1984 manual still my guide to all things engine oil?
> > --
> > Jack "Rocket j Squirrel" Elliott
> > 1984 Westfalia, auto trans,
> > Bend, Ore.
--
David McNeely
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