[Fot] Modern Motor Oil and Your Car

[Gary]

Hello All:

Several months ago the subject of modern oil formulations and their effect on
our flat-tappet equipped engines was discussed here.  One CSRG members, Harlan
Halsey, decided to investigate and found some interesting information.  The
following is a summary of his findings.

Gary
62 TR-4

On ZDDP



When I was a boy growing up on Long Island during the war gas stations sold
oil both in cans and in bulk. Stations usually had three rectangular 40 gallon
tanks with pumps on top at the back of a service bay, and a shelf with
pre-filled 20W, 30W and 40W glass bottles on it. The bulk oil was cheaper, and
although the stations held that it was the same stuff, most people believed
that the canned oil was somehow better. We also watched to see that the glass
bottle was completely emptied into the engine; we wanted every drop we paid
for! By 1963 when I bought my first Porsche, Pennsylvania oils were thought to
be best (Quaker State Racing oil in the engine, Oilzum in the transmission,
AMOCO "no lead" white gas in the tank, and off to Thompson or Lime Rock with
the Lotus). I used Quaker State oil exclusively both on the track and on the
street. But by sometime in the 1970's Quaker State became Pennsylvania "grade"
oil signifying that the base stock no longer came exclusively from the
Pennsylvania wells.  In the 1990's I learned that Kendall Oil was the best
stuff, and used it exclusively until, a few years ago, I heard the Kendall Oil
had changed and that some recent camshaft failures were thought to be traced
to that oil. I changed to Mobil 1 and SWPCO. And then I read several articles
alleging that the Kendall  Oil problem was traced to the reduction of ZDDP. In
the interests of longevity of my 60's era cars I decided to look into the ZDDP
situation. I called and spoke with technical people at The American Refining
Group-Brad Penn Oil, SWEPCO and Exxon Mobil. Brad Penn and SWEPCO were very
helpful. Exxon Mobil, even on their technical line, was not. Here's what I
found:

ZDDP is a molecule which reacts to pressure in such a way as to prevent metal
to metal contact in high pressure places. It will not be easy to replace this
function. This is especially important for "flat" tappet cam followers, and
grows more important the higher the valve spring force. Higher valve spring
forces result from longer duration or higher the RPM, the way 90 HP production
cars were turned into 130HP SCCA "production" race cars in the 60's. Modern
cars are engineered around this by using overhead cams or roller followers, so
we, with older technology, are part of a shrinking market. There may be
substitutes for ZDDP, but as the engine technology has moved on, the effort
toward finding one will not be as it was in the mainstream we were used to.

ZDDP was first added to engine oils sometime between the late 30's and the mid
1940s. All post war high performance cars depend on it. It is an additive for
which they were engineered.

There is a limit to how much ZDDP is beneficial because too much causes
harmful deposits in the engine and can cause piston ring sticking. Between .1%
and .2% by weight seems to be about right.

The current flap over ZDDP probably originated because it was found that
catalytic converter life could be extended if the amount of Phosphorous in
motor oils were to be reduced. But what exactly is mandated, and by whom, is a
bit murky: There seem to be four players in this game; the American and
Japanese car companies, the API (American Petroleum Institute), the ILSAC (
International Lubricant Standardization and Approval Committee) and Big
Brother. The car companies are interested in longer catalytic converter life
for warranty cost reasons. The ILSAC's purpose seems to be to deal with
current cars and certify oils for those cars. These cars use only 0W20or 30,
5W20or30, and 10W30. The API is a "branding" agency like Good Housekeeping or
the UL. The latest API SM approval follows the ILSAC lower ZDDP only for the
ILSASC oils, not (yet) for the heavier 40W and up oils. This means that the
oil companies can, for the moment, use greater amounts of ZDDP in their 40W
and up oils and still get an API SM rating. It does not mean that they do.

Jim Shannon of the American Refining Group wrote, ".in regards to the
reduction of Zinc dialkyl dithio phosphate (ZDDP, ZnDTP, or ZDP) in the SM
rating . the reduction is the result of the EPA mandated reduction of the
phosphorus content in Passenger Car Motor Oil (PCMO).  The phosphorus is @ 90%
of the ZDDP additive system.  As a guideline, the phosphorus ppm limits for
most recent API service categories are: SH-1200, SJ-1000, SL-1000 and SM-800.
The primary viscosities involved in these PCMO categories are the lower
multi-vis formulations e.g. SAE 5W-20, 5W-30 and 10W-30.  This is due to the
fact they fall under ILSAC energy conserving viscosity guidelines and are also
the viscosities recommended in the [modern car] Original Equipment
Manufactures (OEMs) owner's manuals."  Thus it is not yet mandated that all
oils have limited amounts of ZDDP. And the appearance of am SM rating does not
necessarily mean that the oil has less than .8% ZDDP.  Some gasoline engine
oils such as Mobil 1 15W50 EP, and SWEPCO 20W50 and 15W40, have "much more
than 1% ZDDP". And diesel engines require ZDDP in the piston pin area because
of high loading, so to date diesel engine oils (API CI-4 and earlier) are
unaffected.

At least three of the smaller oil companies have responded to the ZDDP flap
and continue to produce high (>.1%) ZDDP oils: SWEPCO is one, Motor Head Hi-Z,
is another and Brad Penn Lubricants, producing Penn Grade 1 Racing Oil is a
third. SWEPCO oils and other products can be purchased through Pat Dewitt in
Sacramento (916-996-1072), Motor Head Hi-Z advertises in Skinned Knuckles
magazine (800-242-8649), and Penn Grade 1 Racing Oil is the original Kendall
Oil Refinery advertising in Circle Track magazine (local source is Karmont
Development in Danville, CA.  The contact there is Monte Berney, and he can be
reached at (925) 766-4680; www.amref.com).

Apparently when Kendall Oil was sold, only the brand name went to Conoco
Phillips. The Bradford, PA refinery cannot refine anything other than the
original Pennsylvania grade crude.  Conoco Phillips didn't want it. So the
American Refining Group is operating the Bradford refinery and producing the
original Kendall oils under the name Brad Penn Premium Pennsylvania Grade
Lubricants and producing high ZDDP oils.

Whether the reduction in ZDDP from .1% to .08% will make a difference or not
is unclear. But what is disturbing is that the oil companies' interest is no
longer aligned with ours. We can no longer take it for granted that oil
companies will produce the best oil of which technology is capable for the
price, and that over time engine oils will continually get better, or that we
will know about changes affecting us as they occur. With Big Brother in the
picture, oils may get worse in the future in order to meet some criteria other
than engine longevity. We may not know about it until it is too late. The
Kendall-Conoco-Phillips situation is illustrative: The stuff now labeled as
Kendall is made by another company without any indication of that on the
label. The engineer answering the Mobil telephone technical line (800-662-4525
option 3) refused to tell me how much ZDDP is in the various types of Mobil 1
citing company confidentiality. But he assured me that for now, the API-SL
rated Mobil1 15W50 EP has "much more" than 1% ZDDP. The engineer I spoke to on
a subsequent call about the non EP, API-SM rated version of the 15W50 refused
to give any information about ZDDP levels other than to say that there is more
of it in the EP version. That fact alone is suggestive. But I rather doubt
that if in the future Mobil decides to lower the amount of ZDDP they will let
anybody know.

There are engine oil supplements such as GM's EOS and STP 4-Cylinder Oil
Treatment, but these are not pure ZDDP, and do not specify the amount of ZDDP
in them-if any. So they would seem to be useless for the purpose of adjusting
the ZDDP level in deficient oil. (EOS has been around for ages, it is a
component of Win Lube, with which we faithfully slather our new camshafts. But
since the contents are not disclosed, who knows if today, it is even the same
stuff we have been using?)

One obvious solution is to stock up now on enough of the good stuff to last a
few racing seasons-assuming that vintage racing isn't banned altogether as
contributing to global warming! (In that case, there's always Neville Shute's
solution). If you stock up, you'll have enough time to figure out what to do
until a source of ZDDP is found and we know how to use it, or we find we can
live without it. Who knows, in the future, getting a little ZDDP may become as
exciting as was getting a copy of "Lady Chatterley's Lover" in the 50's.

Harlan Halsey