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Re: Synthetic Motor Oil

>To:Rudy Moehrbach <Rudy_Moehrbach@p2pays.org>
>From:wjw5@psu.edu (Warren J. Weaver)
>Subject:Re: Synthetic Motor Oil
>You raise many good questions. I'll give them my best shot.
>Though I was trained as a chemist, I am reporting my synthetic oil
>experience as empirical evidence. I have not backed it up with analytical
>tests or scientific data. And it has been some time since I've reviewed
>that information in the literature. To get the real skinny, you need to be
>exchanging e-mail with a petroleum engineer. With that caveat, here's my
>From an application perspective, synthetic is better because the product
>is made to meet certain specifications by engineering and synthetically
>manufacturing a very narrow range and type of organic molecules which have
>the desired chemical and physical properties. With petroleum based oil,
>the manufacturer starts with crude oil which consists of tens of thousands
>of actual or possible types of molecules (from very short, highly volatile
>ones to very long highly viscous ones). During the refining process, the
>crude is "cracked" and distilled-i.e. the long molecules are split into
>smaller components and the motor oil "fraction" is segregated from other
>fractions (some consisting of larger and some consisting of smaller
>molecules) by the fractional distillation process (based on different
>compounds having different boiling points at different temperatures).
>Fractional distillation does not allow you, for example, to selectively
>segregate only organic molecules containing 20 carbon atoms. Instead you
>get a distribution of molecules from say C10 to C30, or C25 to C35 with
>the largest number of molecules having 20 carbon atoms. The rest would be
>present in quantities distributed under a bell shaped curve.
>By chemically engineering the desired molecules, the product does not
>contain any undesireable molecules. Thus every molecule in synthetic oil
>is there for a reason, not because it was too difficult or too expensive
>to remove from the motor oil fraction of crude oil. This means, then, that
>in synthetic motor oil only molecules which are desireable are present.
>Conversely, there will be no molecules that are undesireable to an
>internal combustion engine (or that are easily broken down onto
>undesireable molecules under the extreme conditions occurring in an engine
>(e.g. organic acids, alkenes, alkynes, ketones, aldehydes, organo-nitrogen
>compounds, etc.). It is the absense of these undesireable molecules that
>optimizes thermal stability (i.e. the Mobil 1 commercial of the two motor
>oils being fried on a stove-this should have sold you right there) and
>lubricity. Again, I can't refer you to the data that backs this up, but it
>has been documented that comparing identical engines with synthetic oil in
>one and standard oil in the other, the engine which used synthetic oil got
>the better gas mileage (i.e. less friction; better lubricity).
>In response to your question about thickening up in cold weather, its a
>matter of degree. If you took a standard 30 viscosity synthetic and a 30
>viscosity refined oil, the standard oil would thicken up much more
>significantly than the synthetic. This is mitigated somewhat when you
>compare multi-viscosity oils. Multi-viscosity oils (both standard and
>synthetics) have an additive which consists of long chain polymers which
>coil up at high temperatures and straighten out at low temperatures. When
>coiled, the additive is more viscous that when straightened. Thus at
>temperatures where the base oil tends to be most viscous, the additive is
>least viscous and vice versa. This allows the manufacturer to tune the oil
>to be within the desired viscosity range at all temperatures. This
>additive is virtually the same for both types of oil, though the quantity
>needed will vary. Just by the nature of this additive the difference in
>viscosity change is lessened between the two types of oils. (In North
>Carolina, you should never need 5 W 30. 10 W 30 should be more than
>adequate for cold weather starting for you. 5 W 30 is made for the
>Canadians and the Minnesotans. Also, don't use 40 weight oil or its
>multi-viscosity variants (e.g. 10 W 40). Auto manufacturers no longer
>recommend it. Something to do with back pressure which works against
>lubricity and makes your oil pump work significantly harder.
>I agree with you that a car with 76,000 miles in this day and age is a
>young car. You are not alone in getting over 200,000 miles out of a car.
>To do so, one must take excellent care of a car and RELIGIOUSLY change oil
>every 3000 miles. The large majority of drivers don't do this. Synthetic
>is definitely for them; it may not be for you. Were you to buy a new
>vehicle expecting it to go 235,000 miles, but do the same experiment I've
>been doing (e.g. change the oil every 10,000 miles using synthetic oil)
>and it only lasted 200,000 miles, you would consider the experiment a
>failure and you'd be mad at me for suggesting it. On the other hand, if it
>went 300 or 400,000 miles, you might be mad at me because you can't kill
>an ugly vehicle which doesn't have all the newest fuel efficient and
>convenience features! And if you used synthetic oil and changed it every
>3000 miles as you currently do, you might be mad at me for making your
>lubrication program more expensive (though you will probably more than
>offset this with better fuel mileage-unquantifiable though it would be).
>Why does your car use a quart of oil? Does it leak out? Does it volatilize
>through the PCV valve? Does it pass by the rings and burn in the
>combustion chamber? With refined motor oil, its probably some of each
>(after 235,000 miles, the majority is most likely being burned). When I
>change my synthetic oil after 10,000 miles, the oil level is still at the
>"Add" mark on the dipstick-even after 76,000 miles (others probably have
>even better performance to report). And its only turned about as black
>(dirty) as refined oil is after 3000 miles.
>I agree with you about the concern of break down products from combustion
>creating organic acids in the crankcase. That was my biggest fear as I did
>my "test". I have no scientific data to show whether this was better or
>worse. Theoretically, it should be much better. Here's why. If an engine
>is ideally lubricated every second of its use, there will be very little
>wear. If the rings stay as new as the day the car was built, there will be
>very few products of combustion passing by the rings. That and superior
>resistance to breakdown at 400+ temperatures means synthetic oil stays
>cleaner than refined oil even after extended use. Another advantage is
>synthetic oil's superior film forming capabilities. This means that if you
>let your car sit for two weeks with out running it, there is still a
>significant film of oil on all of the metal parts, something that is not
>always the case with refined oils. Thus, the chance of excessive engine
>wear for the first few seconds during and after starting an engine that
>has been sitting for an extended period of time is significantly lower
>(roughly half of the wear occuring in an engine comes in these few seconds
>with conventional oil-don't know how this compares for synthetics).
>Re your question about how fast synthetic oil gets dirty, its a visual
>assessment based on looking at the dipstick. But it is entirely logical
>that this should be the case based on how it is made and what's NOT in it.
>And my emperical evidence, unscientific as it is, confirms that.
>Your discussion about the 39 micron particles of dirt is a good one. All
>motor oil will get dirty. And the dirt contributes to wear. But when you
>are using an oil which has been chemically engineered to be optimal for an
>application, when it does lubricate better under all types of conditions
>(urban taxicabs, to earth movers on the frozen tundra to printing
>equipment, to Granny's car that sits for three weeks between uses), when
>it resists thermal breakdown, minimizes engine wear, minimizes
>contaminants and performs as well after 6000 miles at regular oil does
>after 3000 (I'm tempted to use 10,000 miles, but I can't state that this
>is true) its worth paying a little more for.
>Re recycling, since the molecules in synthetic oil are identical to the
>ideal ones in refined oil there is no problem in recycling synthetic with
>other used oils. The only disadvantage is that by mixing synthetics in
>with refined oils, the superior performance of the synthetic has been
>compromised by the inferior properties of standard oils when re-refined.
>If the oil is blended for fuel, no problem except that it makes a more
>expensive fuel.
>Also, please note that when I say synthetic oil, I'm talking about oil
>that is 100% synthetic. I would not buy an oil that is a synthetic blend.
>These oils still contain molecules that are not optimized to lubricating a
>car engine. Therefore they are not worth the extra money. Either buy 100%
>synthetics or stick with your standard oil and change the oil every 3000
>miles RELIGIOUSLY! As for me, I'll take the synthetic. In this case, man
>made is better than nature.

>>Like you, I have been following the development of this oil for many years.
>>I do my own car maintenance and would love to use it, but I still have
>>doubts. It provides better lubrication? It is true it does not thicken up in
>>cold weather like a single grade motor oil, but I use 5W30 petroleum motor
>>oil. Does it lubricate better than that? I don't know and I have not seen
>>tests that convince me. In North Carolina a car with 76,000 miles is just
>>breaking in. I have one that is driven daily and has 235,000 miles on it. I
>>change the oil every 3,000 miles on it. The engine is original. Uses about
>>one quart of oil every 1,000 miles. My other car has 120,000 miles on it and
>>runs like new. You say the synthetic oil stays cleaner. How do you know
>>that? Is that better? If I had used synthetic oil on my 16 year old car
>>would the engine be running better? I don't know. It runs very good with
>>235,000 miles on it. I am concerned that the synthetic oil may in fact be
>>dirtier and more harmful to the engine. The typical automotive oil filter is
>>about 30-40 micron. The running clearances are greater than that, but
>>something is wearing out the engine. The longer the oil is in the engine the
>>more dirt of 39 micron or less it will carry. I'm also concerned about the
>>acids that form in the crankcase from combustion blow-by. Supposedly these
>>acids will attack the bearings. The acids are removed when the oil is
>>changed. When your used synthetic oil is recycled, does it get mixed in with
>>used petroleum oil and is this a problem? In industry I worked on air
>>compressors. We were using synthetic oil 25 years ago. It can solve many
>>problems. It also created some problems. I was able to test oils then, but
>>not now. Since I want to use synthetic oil in my cars, I hope other
>>P2TECHers will offer data/experience/advice.
>>Rudy Moehrbach
>>Waste Reduction Resource Center
>>Raleigh, NC
>>Tel 1-800-476-8686, Fax 919-715-1612
>>Web Page http://wrrc.p2pays.org/


Warren J. Weaver
227 W. Market St.
York, PA 17401

ph: (717) 848-6669

fax: (717) 854-0087

website: www.penntap.psu.edu