Date: Sat, 18 Sep 1993 13:27:09 GMT
Sender: Vanagon Mailing List <vanagon@vanagon.com>
From: cac@mtmis1.mis.semi.harris.com (Clint Chamberlin)
Subject: Re: Make Best of Synthetic Oil?
JIE YUAN, CHEMISTRY, U. CINCINNATI (yuanj@ucbeh.san.uc.edu) wrote:
: Just some thoughts about the synthetic oil:
: Almost all the products in the marcket are possibly silicone type,
: very resistant to oxidation, and would last very long. How do one
: filter out the junk in the oil circulation system to take full
: advantage of the synthetic oil? Synthetic oil is very expensive.
: It does not make sense to change it often. But the engine will
: generate some sediments no matter what oil is used. Too much of the
: junk will degrade the lubricating function of the oil.
: Redesign the lubrication system?
: Can't all the cars, at least all the newly designed cars, utilize
: synthetic oil? It must save a lot of oil and do tne environment a
: lot of good!
You are right on all counts. Try AMSOIL spin on filters that remove 1
micron particles as opposed to std FRAM and AC that remove 25 micron.
AMSOIL also has a bypass filter that essentially elminates the need to
change oil. Many truckers never change their oil with this. It costs
around $109 retail(you can get it for $89 as a dealer. Call
715-393-7101 for a dealer near you or more info.
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OIL ... by Ed Hackett The Desert Research Institute
edh@wheeler.wrc.unr.edu Reno, NV (702) 673-7380
First, I will answer a couple of questions asked by another. Yes,
it is OK to mix mineral and syntetic oils. One of the early
synthetics used was a Polyalkylene Glycol. This was totally
incompatable and would gel when mixed. This has not been used for
years for automotive lubrication. All common syntetics used for
engine lubrication now days are a Polyalphaolefin (Mobil 1) or a
Dibasic Organic Ester type (AMSOIL). These are fully compatable
with conventional oils. In fact Golden Spectro and AGIP Sint 2000
are mixtures of mineral and synthetic oils. It is always best to
mix oils with the same rating (SG). This insures that the
additive packages are compatable and will maintain their
effectiveness.
All engine oils use an organic Zinc compound as an extreme
pressure/anti wear additive. Spectro adds more to their Motorcycle
oil than to the car oil because Zinc is a poison to catalytic
converters. You will also see that some "car" oil contains more
than their motorcycle oil. The difference in Zinc content between
.11% and .16% is insignificant to the converter. The little data I
saw on the oils packaged by the motorcycle manufacturers indicated
that they were no better than the top automotive oils. While most
were good, they didn't offer anything the cheaper oils do. (They
are in reality just repackaged and in some cases slightly
reformulated top grade auto oils).
The following is a slightly modified repost of my original article.
I have added a few bits that address some FAQs. (long)
____________________________________________________________________
Choosing the best motor oil is a topic that comes up frequently
in discussions between motoheads, whether they are talking about
motorcycles or cars. The following article is intended to help
you make a choice based on more than the advertizing hype.
Oil companies provide data on their oils most often refered to
as "typical inspection data". This is an average of the actual
physical and a few common chemical properties of their oils. This
information is available to the public through their
distributors or by writing or calling the company directly. I
have compiled a list of the most popular, premium oils so that a ready
comparison can be made. If your favorite oil is not on the list
get the data from the distributor and use what I have as a data
base.
This article is going to look at six of the most important
properties of a motor oil readily availiable to the public: viscosity,
viscosity index (VI), flash point, pour point, % sulfated ash,
and % zinc.
Viscosity is the measure of how thick an oil is. This is
the most important property for an engine. An oil with too
low a viscosity can shear and loose film strength at high
temperatures. An oil with too high a viscosity may not pump to
the proper parts at low temperatures and the film may tear at
high rpm.
The weights given on oils are arbitrary numbers assigned by the
S.A.E. (Society of Automotive Engineers). These numbers correspond
to "real" viscosity, as measured by several accepted techniques.
These measurements are taken at specific temperatures. Oils that
fall into a certain range are designated 5, 10, 20, 30, 40, 50 by
the S.A.E. The W means the oil meets specifications for viscosity
at 0 F and is therefore suitable for Winter use.
The following chart shows the relationship of "real" viscosity to
their S.A.E. assigned numbers. The relationship of gear oils to
engine oils is also shown.
_______________________________________________________________
| |
| SAE Gear Viscosity Number |
| ________________________________________________________ |
| |75W |80W |85W| 90 | 140 | |
| |____|_____|___|______________|________________________| |
| |
| SAE Crank Case Viscosity Number |
| ____________________________ |
| |10| 20 | 30 | 40 | 50 | |
| |__|_____|____|_____|______| |
______________________________________________________________
2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42
viscosity cSt @ 100 degrees C
Multi viscosity oils work like this: Polymers are added to a light
base(5W, 10W, 20W), which prevent the oil from thinning as much as
it warms up. At cold temperatures the polymers are coiled up and
allow the oil to flow as their low numbers indicate. As the oil
warms up the polymers begin to unwind into long chains that prevent
the oil from thinning as much as it normally would. The result is
that at 100 degrees C the oil has thinned only as much as the higher
viscosity number indicates.
Another way of looking at multi-vis oils is to think of a 20W-50 as
a 20 weight oil that will not thin more than a 50 weight would when hot.
Multi viscosity oils are one of the great
improvements in oils, but they should be chosen wisely. Always
use a multi grade with the narrowest span of viscosity that is
appropriate for the temperatures you are going to encounter.
The polymers can shear and burn forming deposits that can
cause ring sticking and other problems. 10W-40 and 5W-30 require a lot
of polymers(synthetics excluded) to achieve that range. This has
caused problems in diesel engines, but fewer polymers are better
for all engines. The wide viscosity range oils, in general, are
more prone to viscosity and thermal breakdown due to the high
polymer content.
Very few manufactures recommend 10W-40 any more, and some
threaten to void warranties if it is used. It was not included
in this article for that reason. 20W-50 is the same 30 point
spread, but because it starts with a heavier base it requires
less viscosity index improvers (polymers) to do the job. AMSOIL
can formulate their 10W-30 and 15W-40 with no viscosity index
improvers but uses some in the 10W-40 and 5W-30. Mobil 1 uses no
viscosity improvers in their 5W-30, and I assume the new 10W-30.
Follow your manufacturer's recommendations as to which weights are
appropriate for your vehicle.
Viscosity Index is an empirical number indicating the rate of
change in viscosity of an oil within a given temperature range.
Higher numbers indicate a low change, lower numbers indicate a
relatively large change. The higher the number the better. This
is one major property of an oil that keeps your bearings happy.
These numbers can only be compared within a viscosity range. It is
not an indication of how well the oil resists thermal breakdown.
Flash point is the temperature at which an oil gives off vapors
that can be ignited with a flame held over the oil. The lower
the flash point the greater tendancy for the oil to suffer
vaporization loss at high temperatures and to burn off on hot
cylinder walls and pistons.
The flash point can be an indicator of the quality
of the base stock used. The higher the flash point the better.
400 F is the minimum to prevent possible high consumption.
Flash point is in degrees F.
Pour point is 5 degrees F above the point at which a chilled oil
shows no movement at the surface for 5 seconds when inclined.
This measurement is especially important for oils used in the
winter. A borderline pumping temperature is given by some
manufacturers. This is the temperature at which the oil will
pump and maintain adequate oil pressure. This was not given by
a lot of the manufacturers, but seems to be about 20 degrees F above
the pour point. The lower the pour point the better. Pour point
is in degrees F.
% sulfated ash is how much solid material is left when the oil
burns. A high ash content will tend to form more sludge and
deposits in the engine. Low ash content also seems to promote
long valve life. Look for oils with a low ash content.
% zinc is the amount of zinc used as an extreme pressure, anti-
wear additive. The zinc is only used when there is actual
metal to metal contact in the engine. Hopefully the oil will do
its job and this will rarely occur, but if it does, the zinc
compounds react with the metal to prevent scuffing and wear. A
level of .11% is enough to protect an automobile engine for the
extended oil drain interval, under normal use.
Those of you with high reving, air cooled
motorcycles or turbo charged cars or bikes might want to look
at the oils with the higher zinc content. More doesn't give you
better protection, it gives you longer protection if the rate of
metal to metal contact is abnormally high. High zinc content
can lead to deposit formation and plug fouling.
The Data:
Listed alphabetically --- indicates the data was not avaliable
Brand VI Flash Pour %ash %zinc
20W-50
AMSOIL 136 482 -38 <.5 ---
Castrol GTX 122 440 -15 .85 .12
Exxon High Performance 119 419 -13 .70 .11
Havoline Formula 3 125 465 -30 1.0 ---
Kendall GT-1 129 390 -25 1.0 .16
Pennzoil GT Perf. 120 460 -10 .9 ---
Quaker State Dlx. 155 430 -25 .9 ---
Shell Truck Guard 130 450 -15 1.0 .15
Spectro Golden 4 174 440 -35 --- .15
Spectro Golden M.G. 174 440 -35 --- .13
Unocal 121 432 -11 .74 .12
Valvoline All Climate 125 430 -10 1.0 .11
Valvoline Turbo 140 440 -10 .99 .13
Valvoline Race 140 425 -10 1.2 .20
20W-40
Castrol Multi-Grade 110 440 -15 .85 .12
Quaker State 121 415 -15 .9 ---
15W-50
Chevron 204 415 -18 .96 .11
Mobil 1 180 430 -55 --- ---
Mystic JT8 144 420 -20 1.7 .15
15W-40
AMSOIL 135 460 -38 <.5 ---
Castrol 134 415 -15 1.3 .14
Chevron Delo 400 136 421 -27 1.0 ---
Exxon XD3 --- 417 -11 .9 .14
Exxon XD3 Extra 135 399 -11 .95 .13
Kendall GT-1 135 410 -25 1.0 .16
Mystic JT8 142 440 -20 1.7 .15
Shell Rotella w/XLA 146 410 -25 1.0 .13
Valvoline All Fleet 140 --- -10 1.0 .15
Valvoline Turbo 140 420 -10 .99 .13
10W-30
AMSOIL 142 480 -70 <.5 ---
Castrol GTX 140 415 -33 .85 .12
Chevron Supreme 150 401 -26 .96 .11
Exxon Superflo Hi Perf 135 392 -22 .70 .11
Exxon Superflo Supreme 133 400 -31 .85 .13
Havoline Formula 3 139 430 -30 1.0 ---
Kendall GT-1 139 390 -25 1.0 .16
Mobil 1 --- 430 -60 --- ---
Pennzoil PLZ Turbo 140 410 -27 1.0 ---
Quaker State 156 410 -30 .9 ---
Shell Fire and Ice 155 410 -35 .9 .12
Shell Super 2000 155 410 -35 1.0 .13
Shell Truck Guard 155 405 -35 1.0 .15
Spectro Golden M.G. 175 405 -40 --- ---
Unocal Super 153 428 -33 .92 .12
Valvoline All Climate 130 410 -26 1.0 .11
Valvoline Turbo 135 410 -26 .99 .13
Valvoline Race 130 410 -26 1.2 .20
5W-30
AMSOIL 168 480 -76 <.5 ---
Castrol GTX 156 400 -35 .80 .12
Chevron Supreme 202? 354 -46 .96 .11
Exxon Superflow HP 148 392 -22 .70 .11
Havoline Formula 3 158 420 -40 1.0 ---
Mobil 1 150 430 -65 --- ---
Mystic JT8 161 390 -25 .95 .1
Quaker State 165 405 -35 .9 ---
Shell Fire and Ice 167 405 -35 .9 .12
Unocal 151 414 -33 .81 .12
Valvoline All Climate 135 405 -40 1.0 .11
Valvoline Turbo 158 405 -40 .99 .13
All of the oils above meet current SG/CD ratings and all
vehicle manufacture's warranty requirements in the proper viscosity.
All are "good enough", but those with the better numbers are icing on
the cake.
The more expensive synthetics; AMSOIL, Mobil 1,
and Spectro offer the only truly significant differences, due
to their superior high temperature oxidation resistance, high film
strength, very low tendancy to form deposits,
stable viscosity base, and low temperature flow characteristics.
Synthetics are superior lubricants compared to
traditional petroleum oils. You will have to decide if their high
cost is justifed in your application.
The extended oil drain intervals given by the vehicle
manufacturers(typically 7500 miles) and synthetic oil companies(up
to 25,000 miles)
are for what is called normal service. Normal service is
defined as the engine at normal operating temperature, at
highway speeds, and in a dust free environment. Stop and go,
city driving, trips of less than 10 miles, or exterme heat or cold puts
the oil change interval into the severe service category, which is
3000 miles for most vehicles. Synthetics can be run two to three
times the mileage of petroleum oils with no problems. They do not
react to combustion and combustion by-products to the extent that
the dead dinosaur juice does. The longer drain intervals possible
help take the bite out of the higher cost of the synthetics.
If your car or bike is still under warranty you will have
to stick to the recommended drain intervals. These are set for
petroleum oils and the manufacturers make no official allowance for
the use of synthetics.
Oil additives should not be used. The oil companies have gone
to great lengths to develop an additive package that meets the
vehicle's requirements. Some of these additives are synergistic,
that is the effect of two additives together is greater than the effect
of each acting separately. If you add anything to the oil you may
upset this balance and prevent the oil from performing to
specification.
The numbers above are not, by any means, all there is to determining
what makes a top quality oil.
The exact base stock used, the type, quality, and
quantity of additives used are very important.
The given data combined with the manufacturer's
claims, your personal experience, and the reputation of the oil
among others who use it should help you make an informed choice.
----------------------------------------------------------------------
I just recieved this data from our local oil distributor. It is
the update on the new Mobil 1 formulation and that for the new
Castrol Syntec. They did not have the numbers for the new
Valvoline synthetics yet. The data on the new Mobil 1 is pretty
impressive. Based on these numbers, price, and availiability,
there is little need to look further for a synthetic oil.
The Syntec seems to be compromised by it's wide viscosity range.
Notice that the pour point is for all practical purposes, no
better than the Mobil 1 15W-50. (actually, it's not as good)
While, meeting the viscosity parmeters, the wide range is
probably for marketing purposes. The Mobil 1 15W-50 will pump at
-35 degrees F, which is as good as some conventinal 5W-30 oils.
Any of the ester based synthetics (AMSOIL, Mobil 1, and Syntec),
will give you the benefits that Castrol is making a big deal of in
their advertising. The ability to cling to metal walls is due to
the polar nature of the ester base stock, not something unique to
Castrol's formulation.
The Data: (add to your current article)
Brand and Weight VI Flash Pour %ash %zinc
Syntec 5W-50 180 437 -49 1.2 0.10
Mobil 1 5W-30 165 445 -65 --- ---
10W-30 160 450 -65 --- ---
15W-50 170 470 -55 --- ---
========================================================================
Number Crunching - the lowdown on Volkswagen's part numbering system.
by Timothy N. Gavern, with special thanks to John Ludwig
(VW TRENDS, March 1992)
If you've been around Volkswagens a while, you have probably caught on
to the fact that there is a system to their parts numbers. A good VW
parts man can usually go to the shelf and get the part you came in for
without even looking it up in the book. Of course, he probably double-
checks to be sure that he has the right one ... But, the reason that he
can pull parts this way is because Volkswagen had the foresight in it's
infancy to develop an extremely efficient nine digit system of numbering
(with letters of the alphabet sometimes appearing as suffixes).
This system makes it easy for him (or her) to come up with the correct
part because of how the part number identifies what the part is. The
nine digit number starts off with three digits indicating what type,
model, or version of car (or truck) the part is for. The following
digit is the main group that the part is from. The following two digits
are the sub-group identifiers and the last three digits are the part's
actual number within the group and sub-group. If there are any letters
following the number, they are the modification code. Sound difficult?
Look at this example and you will see how simple it really is.
Part number 176 867 009 C MT3 is a blue left door trim panel for a
Golf 2-door. The breakdown to identify the part goes like this:
The first three digts, "176", distinguish the Type, Model, or Version
of the vehicle (Golf, 2-door).
The following number, "8", is the main group number from which the part
is from (Body). <sic>
Next, the two digits, "67", indicate the sub-group number (Door trim
panels, side trim panels, trunk linings, roof and pillar linings,
and grab handles)
followed by "009 C" which is the part's number (Left side, front door
panel).
Following the part number is the "MT3" modification code (Blue).
A further breakdown of the part number is in order here. It is
important to remember that the first three digits indicate the type,
model, or version only for which the part was originally designed.
This could confuse people sometimes, but realize that parts can also be
used on other vehicles and because of this fact the first three digits
do not etch in stone that the part is for only one particular vehicle.
Think about the case of an oil dipstick. Why should Volkswagen make
five different ones when one could suffice for several vehicles. Hence,
your dipstick part number could have a different first three digits
than the digits that indicate your model. In this case, the first three
digits would indicate which car model or type the dipstick was originally
designed for ... not the model you have. Simple.
Next digit in the part number are the group number, the groups are
broken down into ten categories (or groups). <sic> The one digit
indicates which group the part is from.
1. Engine
2. Fuel tank, exhaust system, heating and air conditioning
3. Transmission
4. Front axle, steering, differential
5. Rear axle
6. Road wheels, brakes
7. Hand-lever system, pedal cluster (frame)
8. Body
9. Electrical
10. Factory accessories such as jacks, tools, and stickers
In the case of the part number that we identified above, Group 8
indicates that it was a body part.
The subgroup is the next identification; which follows the group number
and is indicated by a two digit code. In our case, "67", which means
section 67 of the main group 8 in the Golf microfiche. This makes
finding the part in the microfiche much easier and faster.
Following the subgroup is the actual part number or "actual" numerical
designation. "009" is the actual part number. Actually, the ninth
digit in the part number is the part's real number. In our example,
it is an odd number (9). Odd numbers usually indicate a left side part
and even numbers usually indicate a right side part. Those parts which
could be used on either side usually have an odd ninth number. Our part
is a left side door panel, so the number is odd. Note: It is very
important to remember that left, right, front, rear are determined from
the driver's seat in driving position.
Last, but not least, is the modification code at the end of our number.
These are added to the part number if the part has been modified or
changed. This means if the part has been changed to different
materials, construction of the part has changed, or even if the supplier
has changed. The "C" indicated in our part number could be a
manufacturing plant code, a change in materials, or whatever. These
parts with modification codes may or may not interchange with parts
having the same part number and no modification code. These letters
also very importantly can tell you what color the part in question is.
As in our case, where "MT3" signifies the color blue.
One last important thing to remember is not to confuse the chassis
numbers (VIN numbers) with part numbers. The part numbers only indicate
the parts that make up a vehicle, but the chassis number simply
distinguishes one vehicle from another. We hope this article will make
it a little easier for you to understand Volkswagen's part numbering
system and that you are a little more appreciative of the fact that
their system works so well.
........................................................................
i'm not sure when vw put this system into effect, so i don't know if
it applies to the oldest generation of buses. as i recall, the 2nd
generation of buses had part numbers usually beginning with 211.
vanagon part numbers usually begin with 251. eurovan part numbers
(i think) begin with 700.
this does NOT apply to electrical parts, or tranmission parts. electric
parts seem to start mostly with 025 (which seems to be a designation for
Bosch). transmission parts seem to start with the type of transmission
... that is, an air-cooled vanagon 4-speed has a 091 transmission, and
parts for that transmission would start with 091. a vanagon syncro
transmission is an 094, and its parts (but only those SPECIFIC to the
Syncro) would start with 094. any 094 parts that are common to the 091
would start with 091.
it's kinda neat to notice that the Oh-my-God-straps in the campers,
those grab-and-hang-on straps for the rear seat passengers, start with
113 ... the old faithful Beetle. :)
=========================================================================