[xj-s] my two bits worth on oils

XJ-S
1

The worst engine I ever rebuilt was a Chevrolet 350
which had run on Pennzoil since the day it was new. It
was totally sludged up and the filthiest mess
imaginable. Later , while working in a dealership we
took a Monte Carlo in which was a Quaker State user,
and it wouldn’t drain. We ultimately flushed it with
Diesel fuel to clean the pan out. I personally
wouldn’t use either of those brands to hold dust down
in my driveway.
Pure synthetic oil does not work well in engines which
use heavily leaded fuel, such as piston engined
aircraft as the base does not hold lead salts in
suspension and it precipitates out in the form of a
gray goo known in the industry as “Gray Paint” In an
engine which does not use leaded fuel, such as jets
and any automobile built in the last couple of decades
it’s hard to beat. The chief advantage of synthetic
oils is there longer lifetime. Contrary to what used
to be stated as fact, oil does wear out. Under the
scanning electron microscope it was determined that
the long hydrocarbon chains which make up lubrication
oil are “chopped up” in the course of performing their
duty. The synthetics can be built up with much longer
chains which take longer to break down. The semi
synthetic has proven to be an excellent alternative in
the aviation industry. If one is going to adhere to a
fairly short change interval such as 5000 miles, I
personally can see no real advantage to the full
synthetic over the semi. If the decision is made to
use the full capability of the synthetic oil it would
probably be necessary to run the oil for 10000 or more
miles, but that is more than most of drive our cars in
a year, which ushers in a host of new problems such as
acid build-up in the oil. I personally run Valvoline
semi-synthetic in the Jaguar and Aeroshell 15w50 in
the plane.
Tom Wilson=====
Everybody knows the boat is leaking…Everybody knows the captain lied

Do You Yahoo!?
Yahoo! Health - Feel better, live better

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2

tom wilson wrote:

The worst engine I ever rebuilt was a Chevrolet 350
which had run on Pennzoil since the day it was new. It
was totally sludged up and the filthiest mess
imaginable. Later , while working in a dealership we
took a Monte Carlo in which was a Quaker State user,
and it wouldn’t drain. We ultimately flushed it with
Diesel fuel to clean the pan out.

I have heard LOTS of stories like that – all relating to dino oils
originating from Pennsylvania oil fields. Apparently the makers are
proud of the Pennsylvania origin, indicating it right in the name –
Pennzoil, Quaker State, etc. I can’t say I’ve ever heard a good
thing said about a Pennsylvania-based motor oil.

Pure synthetic oil does not work well in engines which
use heavily leaded fuel, such as piston engined
aircraft as the base does not hold lead salts in
suspension and it precipitates out in the form of a
gray goo known in the industry as “Gray Paint”

I’ve seen that goo, never knew what it was! I’m gonna go way out on
a limb here and suggest that it would be possible to formulate a
synthetic for leaded fuels, but nobody as yet has seen a need to.
After all, here in the US finding leaded automotive fuel is tough,
and I understand it’s getting that way in other areas. True,
aircraft still use leaded fuel, but introducing any new product is
terribly expensive and time-consuming in the aircraft biz so perhaps
they just stick with the products that have already met FAA approval
rather than do any development.

– Kirbert

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3

Kirbert wrote:

originating from Pennsylvania oil fields. Apparently the makers are
proud of the Pennsylvania origin, indicating it right in the name –
Pennzoil, Quaker State, etc. I can’t say I’ve ever heard a good
thing said about a Pennsylvania-based motor oil.

There is no doubt a technical explanation AIRC at least one bearing co.
to my knowledge differentiates between Pennsylvania oils and others when
assigning life correction factors to bearing life predictions.
Apparently they found Penn oils for the same viscosity did not give
equal bearing life. IIRC to get equal life with a Penn State oil you had
to increase the viscosity at operating temp by about 20-30%.
Richard Griffiths

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4

Kirbert wrote:

(snip)

originating from Pennsylvania oil fields. Apparently the makers are
proud of the Pennsylvania origin, indicating it right in the name –
Pennzoil, Quaker State, etc. I can’t say I’ve ever heard a good
thing said about a Pennsylvania-based motor oil.

Kirby, in the past, Pennsylvania crudes have been preferred for the
production of lubricating oils. Here’s some further info on this topic:

“Motor oils (at least the good ones) are made from paraffin-based crude
oils. Paraffin-based crudes offer much greater stability at extreme
operating temperatures and can be formulated to produce motor oils that are
more resistant to sludge than motor oils derived from naphthenic-based
crudes.”

From
http://www.usace.army.mil/inet/usace-docs/eng-manuals/em1110-2-1424/c-3.pdf,
a fairly detailed document:

"Paraffinic oils. Paraffinic oils are distinguished by a molecular structure
composed of long chains of hydrocarbons, i.e., the hydrogen and carbon atom
are linked in a long molecular series similar to a chain. Paraffinic oils
contains paraffin wax and are the most widely used base stock for
lubricating oils. In comparison with naphthenic oils, paraffinic oils have:

  1. Excellent stability (higher resistance to oxidation).
  2. Higher pour point.
  3. Higher viscosity index.
  4. Low volatility and, consequently, high flash points.
  5. Low specific gravities."

and

"Naphthenic oils. In contrast to paraffinic oils, naphthenic oils are
distinguished by a molecular structure composed of ‘rings’ on hydrocarbons,
i.e., the hydrogen and carbon atoms are linked in circular pattern. These
oils do not contain wax and behave different than paraffinic oils.
Naphthenic oils have:

  1. Good stability.
  2. Lower pour point due to absence of wax.
  3. Lower viscosity indexes.
  4. Higher volatility (lower flash point).
  5. Higher specific gravities.

Naphthenic oils are generally reserved for applications with narrow
temperature ranges and where a low flash point is desired."

One further quote, with a somewhat different viewpoint:

“When Pennsylvania crude oil is refined, it readily yields a lubricant base
stock that has relatively high resistance to oxidation and a high viscosity
index (that is, its viscosity changes little over a wide temperature range).
This feature was important when separating lubricant stocks from other crude
oils was difficult, but for several decades oil companies have known how to
get equally good lube base stocks from many different crude oils. And
additives are much more important in today’s lubricants, and lube makers
have learned how to adjust for variations in base stocks by modifying the
additive package.”

BTW, Pennsylvania crudes are paraffinic crudes.

Richard, I would be very interested in a reference to the material you
cited, in regards to the inferior bearing lubrication properties of oils
made from Pennsylvania crudes.

Best regards,

Gregory Wells 800-331-2193 x103
Coventry West, Inc. - Atlanta, GA www.coventrywest.com
New, Rebuilt, and Used Jaguar & Land-Rover Parts

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5

Do they still pump oil from Pennsylvania wells? Or, has “Pennsylvania crude”
merely become an expression for a certain type of oil, as opposed to where
it comes from?

FWIW, I’ve heard for many mechanics over the years say they didn’t like
Quaker State or Pennzoil. Of course, it may have just been an old mechanics’
wives’ tale.

Gary
94 4.0L Convertible
San Jose, CA----- Original Message -----

BTW, Pennsylvania crudes are paraffinic crudes.

Richard, I would be very interested in a reference to the material you
cited, in regards to the inferior bearing lubrication properties of oils
made from Pennsylvania crudes.

Best regards,

Gregory Wells 800-331-2193 x103

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6

Paul C Harris wrote:

So - and don’t bite my damn head off again, Kirbert - is there a
preference in brands of synthetics?

Just about everyone likes Mobil 1. I’ve also heard that Amsoil is
excellent. I haven’t heard a lot about Purple Lightning or whatever
the purple stuff is called, but the little I’ve heard has been good.
I’ve heard a couple bad things about Castrol Syntec, although I think
the main negative there is they don’t seem to make any oil I’d
consider suitable for the Jaguar V12.

If you wanna pick one and stick with it (for whatever reason), pick
Mobil 1 15w-50.

– Kirbert

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7

Paul C Harris wrote:

If you wanna pick one and stick with it (for whatever reason), pick
Mobil 1 15w-50.

Thanks Kirby. Wasn’t Mobil 1 the first widely available synthetic?

I’m no historian, but my impression is that Amsoil invented
synthetics and Mobil 1 made them popular. I’m pretty sure Mobil 1
has been reformulated at least once since then, which is a good
indication that they are keeping abreast of technical developments.

– Kirbert

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