| Author |
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Crusty
| | Posted on Saturday, August 13, 2005 - 03:53 pm: | 
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Any oil is better than no oil. Yes? |
Tramp
| | Posted on Saturday, August 13, 2005 - 04:25 pm: |
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only colonel clink, yoda, and donald pleasance can really pull off that "yes?" nonsense...yes? |
Blake
| | Posted on Saturday, August 13, 2005 - 05:07 pm: |
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Does there even exist a synthetic straight grade 60 wt oil?
The only reason I can imagine that a straight weight oil would perform better is that they don't suffer the same thermal breakdown exhibited by conventional multi-vis oils. Sixty weight oil at room temperature is darn near grease. Maybe that is better for the old bottom ends at startup, before the oil pump starts things circulating? I dunno. |
Tramp
| | Posted on Saturday, August 13, 2005 - 05:18 pm: |
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me either.
i ahd posted here, awhile back, that i was informed, at bmw, that their own full-synth has the ability to go (via molecular chain-'stretch') form 5wt. to 50 wt.; that is, the whole mass of oil essentially stretched it's chain from 5 w @ low temp, to 50 @ high temp.
is that pretty much nonsense, Blake?
(you wanna know about oil, ask a Texan...
you wanna know from Pizza, {en vocce mel gibsonae}, "come talk ta me!" |
Jackbequick
| | Posted on Saturday, August 13, 2005 - 06:25 pm: |
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"Does there even exist a synthetic straight grade 60 wt oil?"
Amsoil has one but finding that might be a little trouble. I priced it off that link, it was $7.65 a qt. in 2.5 gal jugs before shipping costs.
I am *not* advertising or promoting, here is more info on Amsoil MC oils. It offers some interesting details for H-D engines. And a nice explanation of the procession, names, and dates for H-D engines.
And yes, I know they are selling the stuff. This not an endorsement, it is just more info to the topic under discussion.
I started looking at all this stuff months ago when I was considering using synthetic in my just acquired M2. The discussions in the KV won me over to the change. For the record, I have not used any Amsoil products yet.
If I lived in a hotter clime I would probably be giving serious consideration to a single weight.
Jack |
Tramp
| | Posted on Saturday, August 13, 2005 - 06:47 pm: |
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evos really don't need single weight... |
Jackbequick
| | Posted on Saturday, August 13, 2005 - 08:51 pm: |
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You're probably right but if I was riding in higher ambient temps a lot much I'd buy it and feel better about it.
Jack |
Tramp
| | Posted on Saturday, August 13, 2005 - 08:57 pm: |
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as would I, regardless.
it seems reasonable that
a heavy single weight, in
the dead of 100o summer, would be good protection |
Frausty12r
| | Posted on Saturday, August 13, 2005 - 09:45 pm: |
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Tramp,
From what I know about oil weight, and multi-vis, is lets say 20w/50
50 constitutes the LOW TEMP weight, i.e. at startup.
20 constitutes the HIGH temp, or broken weight.
Most i.c.e's use multi weight as the heavier "cold" weight protects against cold starting friction, but as the engine warms, it requires "lighter" lubrication as the oil pump has already circulated oil, and all mating parts have been lubed.
The only reason I could see the benefit of a straight weight oil, is that even when hot, the oil is still thick, and very lubricious (is that even a word? sounds good.. fun to say). When you stop the engine, the oil will "cling" to the parts, so when you do "cold" start the engine, it's almost like having a pre-lubricating system (like they have in High horsepower engines aka spraybar)
So the bmw guy's info is nonsense imo.
(Message edited by frausty12r on August 13, 2005) |
Blake
| | Posted on Sunday, August 14, 2005 - 12:15 am: |
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Not nonsense Jay. That is synthetic oil. |
Brucelee
| | Posted on Sunday, August 14, 2005 - 10:43 am: |
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The following is long but instructive on the properties of Mult VIS vs Straight weight oil. Also includes infor on SYN MG oils.
Monograde oils such as 30 weight oils are designed for consistent temperature applications. For
instance, you will find that most older lawn tractors and mowers call for a straight 30 weight oil (SAE
30). This is because it is assumed that these will be operating mainly in warm temperature summer
months.
So, if you take a look at their viscosity index, you'll notice that most monograde oils have a low VI
number. This implies that as you cool the oil it will thicken quite a bit. However, this is ok, because the
oil is designed to only be used under warm conditions. Cold temperature thickening will not be an issue.
According to SAE J300 standards, to be classified as a certain SAE viscosity, an oil is heated to 100
degrees C (212 degrees F). It's kinematic viscosity at this temperature is measured. If it falls within a
certain range it is classified as a particular viscosity. For instance, an SAE 30 oil must have a kinematic
viscosity at 100 degrees C of between 9.3 and 12.5 cSt (centistokes).
Multi-viscosity (multi-grade) oils such as 0w30, 5w30, 10w40 and so on are oils,
applications where temperature changes may be significant. For instance, multi-viscosity oils might be
used in northern US climates where temperatures can be -20 degrees F in the winter and +95 degrees
F in the summer.
However, that does not mean they cannot be used for applications where the temperature remains
more consistent. The fact is, monograde oils are becoming much less common as multi-viscosity oils
are being substituted in applications which traditionally called for a monograde oil.
Nevertheless, monograde oils are still used in many super high performance racing applications,
construction equipment that is used in only summer months and industrial engines that are kept indoors
at a constant temperature all year round.
WHAT DO THE NUMBERS MEAN?
Most people believe that a 5w30 oil is good for cold weather use because it is a "5 weight" oil in cold
temperatures and a "30 weight" oil at high temperatures. On the surface this might seem to make a
certain amount of sense. Naturally, a "5 weight" oil would flow better than a "30 weight" oil. This would
make it ideal for cold temperature operation.
Nevertheless, this is a profound misunderstanding of what the labeling means. The two numbers really
have little to do with each other. The final number based upon the kinematic viscosity at 100 degrees C,
MONOGRADE OILS
MULTI-VISCOSITY OILS
as we discussed for monograde oils.
So, if a multi-grade oil, when heated to 100 degrees C, falls within a certain kinematic viscosity it is
classified as a certain SAE grade (the last number - like the "30" in 5w30). In other words, the kinematic
viscosity of a 5w30 multi-viscosity oil falls within the same range at 100 degrees C as a monograde
SAE 30 weight oil does.
A multi-viscosity oil also has to meet a "High Temperature/High Shear" requirement, but I'll talk about
that in a minute.
The first number (the "5" in 5w30) is only a relative number which basically indicates how easily it will
allow an engine to "turn over" at low temperatures. It is NOT a viscosity reference. In other words, a
10w30 is NOT a 10 weight oil in cold temperatures and a 30 weight oil in warm temperatures.
In fact, since SAE viscosity classifications only apply to an oil at 100 degrees C, it doesn't even make
sense to label it as a certain SAE viscosity at any temperature other than 100 degrees C.
Besides, if you thought about it for a second, it wouldn't make sense for a 10w30 oil to be a 10 weight
oil in the cold and a 30 weight oil in warm temperatures. What liquid do you know of that gets "thicker"
as its temperature increases or "thinner" as the temperature decreases?
I would venture to say you probably can't come up with one. This holds true for motor oil as well. If a
10w30 was a 30 weight oil at 100 degrees C and a 10 weight oil at cold temperatures, that would mean
it "thinned out" as the temperature dropped. That just doesn't make any sense considering what we
know about liquids. It just doesn't happen like that.
The fact is that a 5w30 motor oil is thicker in cold temperatures than in warm temperatures. However,
a 5w30 motor oil will be thinner than a 10w30 motor oil when subjected to the same low temperature
conditions - because the "W" number is lower. This is an indication of better cold weather performance.
In other words, a 5w30 flows better in cold weather than a 10w30 motor oil will. Think of the "W" as a
"winter" classification instead of a "weight" classification.
Results from the Cold Crank Simulator (CCS) and Mini-Rotary Viscometer (MRV) tests are used to
determine the oil's "W" grade. The better the engine "startability" of the oil at low temperature, the lower
the W classification. Each W grade must meet certain "startability" requirements at a specified
temperature.
For instance, a 0W grade oil must have a maximum CCS centipoise (cP) value of 3250 @ -30 degrees
C as well as a maximum MRV cP of 60,000 @ -40 degrees C. A 5W grade oil must have a maximum
CCS cP value of 3500 @ -25 degree C and a maximum MRV cP of 60,000 @ -30 degrees C. The
lower the cP value for both specifications, the better.
Notice that the 0W grade oil is tested at a lower temperature on both tests AND must still have a lower
CCS cP value than a 5W oil which is tested at a higher temperature. As a result, a 0w30 will allow your
vehicle to start easier on a cold morning than a 5w30 will. Likewise, a 5w30 oil will pump easier in cold
temperatures than a 10w30 oil will.
Nevertheless, at 100 degrees C, they all fall within the same kinematic viscosity range. Therefore, they
are all classified as SAE 30 weight oils at 100 degrees C. In other words, after your engine has warmed
up, a 0w30 and 10w30 motor oil are basically the same thickness (within a certain SAE specified
range).
Of course, although this is true when the oil comes out of the bottle, we'll see in the next section that,
with petroleum oils at least, the viscosity that comes out of the bottle may not necessarily be the
viscosity that you find within your engine after a short period of driving.
Multi-viscosity oils provide a great deal more flexibility to protect an engine over a wider temperature
range than monograde oils do. Obviously, this should be considered a good thing. However, there is a
drawback to multi-viscosity oils. When manufactured from a petroleum basestock, they tend to "shear"
back very easily. In fact, this was already alluded to in the previous chapter.
You see, the waxy contaminants within petroleum basestocks crystalize in cold temperatures causing
them to "thicken" and become hard to pump. So, in order to allow for good flow characteristics at low
temperatures, in addition to using pour point depressant additives, petroleum oils must start with a very
"thin" basestock.
For instance, let's look at a 5w30 motor oil. In order to flow well enough to meet the 5W classification, a
petroleum oil would start with a very thin basestock (maybe one that would be classified as an SAE 20
weight oil if heated to 100 degrees C). Then, that basestock would be combined with pour point
depressant additives.
Remember from the last chapter that these pour point depressants help the basestock maintain its low
viscosity even at low temperatures. They counteract the crystallization of waxy contaminants in the oil.
Thus, the oil maintains it's viscosity instead of thickening up as the temperature drops.
But, in order to meet the requirements to be classified as an SAE 30 oil, something must be done to
assure that this oil won't thin out to it's 20 weight basestock viscosity at 100 degrees C. The oil must be
"built up" using the long-chain, high-molecular-weight polymers (called Viscosity Index Improvers)
discussed in the previous chapter.
These polymers expand as temperature increases counteracting the natural thinning action of heating
an oil. So instead of thinning to a 20 weight classification, the oil only thins to a 30 weight classification.
NOTE: Remember, don't let the 5W fool you. It's not a viscosity classification. It's a classification to
establish that an oil will flow adequately at cold temperatures to protect your engine. The oil is still
THICKER at cold temperature than it is at hot temperatures. The oil will thin as the temperature
increases. The only question is how much. VI improvers reduce this thinning action to acceptable levels
so the oil can meet both the 5W requirements and the SAE 30 requirements.
Now, let me just say that, the more you think about this issue of viscosity, the more your brain is going
to hurt. Just remember that petroleum basestock viscosities are prone to significant change as the
basestock is heated and cooled. As it cools, it "thickens" and as it heats it "thins".
To counteract that, petroleum oil manufacturers start with a basestock "thinner" than the "30" in
"5w30" (or thinner than the "40" if they're manufacturing a 10w40 oil, etc.) and add pour point
depressants so the oil stays as thin as possible in cold weather. Then they add viscosity index
improvers that expand with increases in heat so that the oil will not thin out too much to meet the 30
weight classification at 100 degrees C. This is how they meet the multi-grade specification.
Unfortunately, long chain polymers (VI improvers) are more unstable the longer they are. The nature of
petroleum basestocks necessitates that they be "built-up" using very long chain polymers. Therefore,
these long chain polymers break down fairly quickly. In turn, over a short period of time, a 5w30
petroleum oil may actually "shear back" to a 5w20 (or lower) as these polymers break down. Obviously,
this can lead to a decrease in engine protection.
THE PROBLEM WITH MULTI-VISCOSITY OILS
For this reason, to assure at least a minimum amount of protection, the SAE J300 describes another
requirement that a multi-viscosity oil must meet in order to be given its multi-viscosity classification. It
must maintain a certain cP level on the High Temperature/High Shear (HT/HS) test (ASTM D 4683).
This test must be performed in order to label an oil as a certain multi-grade classification because
automobile manufacturers use the physical requirement standards listed in the SAE J300 in order to
establish which viscosity grades should be used in which vehicles. If automotive and lubricant
manufacturers are not working off the same play book, it's your engine that's at risk.
But, let's get back to the HT/HS test. If the oil shears back too much on this high temperature test, it
cannot be sold as a multi-grade oil. In fact, the test results from this test are very helpful in indicating
the quality of the oil. Since they're required for achieving a certain SAE viscosity grade classification,
the manufacturing company has the data. Make sure you get it.
The higher the HT/HS number the better because this indicates less shearing. Petroleum oils tend to
have low HT/HS numbers which barely meet the standards set by the SAE J300 specifications.
Also, because the petroleum oils are made with a light weight basestocks to begin with, they tend to
burn off easily in high temperature conditions which causes deposit formation and oil consumption.
As a result of excessive oil burning and susceptibility to shearing (as well as other factors) petroleum
oils must be changed frequently.
The good news is, not all multi-viscosity oils shear back so easily. Synthetic oils contain basically no
waxy contamination to cause crystallization and oil thickening at cold temperatures. In addition,
synthetic basestocks do not thin out very much as temperatures increase.
So, pour point depressants are unnecessary AND higher viscosity basestock fluids can be used which
will still meet the "W" requirements for pumpability. In other words, it might be possible to meet 5W
requirements with a synthetic basestock that would be classified as a 25 or 30 weight oil at 100
degrees C. Hence, little or no VI improver additive would need to be used to meet the 30 weight
classification while still meeting 5W requirements.
The result is that very little shearing occurs within synthetic oils because they are not "propped up" with
viscosity index improvers (long chain polymers). There simply is no place to shear back to. In fact, this
is easy to prove by just comparing synthetic and petroleum oils of the same grade. Synthetics will
generally have significantly higher HT/HS numbers. Of course, the obvious result is that your oil
remains "in grade" for a much longer period of time for better engine protection and longer oil life.
THE SOLUTION FOR MULTI-VISCOSITY OILS
The good news is, not all multi-viscosity oils shear back so easily. Synthetic oils contain basically no
waxy contamination to cause crystallization and oil thickening at cold temperatures. In addition,
synthetic basestocks do not thin out very much as temperatures increase.
So, pour point depressants are unnecessary AND higher viscosity basestock fluids can be used which
will still meet the "W" requirements for pumpability. In other words, it might be possible to meet 5W
requirements with a synthetic basestock that would be classified as a 25 or 30 weight oil at 100
degrees C. Hence, little or no VI improver additive would need to be used to meet the 30 weight
classification while still meeting 5W requirements.
The result is that very little shearing occurs within synthetic oils because they are not "propped up" with
viscosity index improvers (long chain polymers). There simply is no place to shear back to. In fact, this
is easy to prove by just comparing synthetic and petroleum oils of the same grade. Synthetics will
generally have significantly higher HT/HS numbers. Of course, the obvious result is that your oil
remains "in grade" for a much longer period of time for better engine protection and longer oil life. |
Tramp
| | Posted on Sunday, August 14, 2005 - 11:01 am: |
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holy redundancy of redundancy of redundancy, batman.
does 'concise' mean anything anymore?
how about citing and/or footnoting.
brucelee, you need to try to use more space to say even less
(just ballbusting, mr. lee)
(Message edited by tramp on August 14, 2005) |
Nitsebes
| | Posted on Sunday, August 14, 2005 - 12:09 pm: |
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He had me at "viscosity" |
Tramp
| | Posted on Sunday, August 14, 2005 - 12:46 pm: |
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i randomly highlit a sentence from mr. lee's extranneously verbose thesis:
"Remember, don't let the 5W fool you. It's not a viscosity classification. It's a classification to
establish that an oil will flow adequately..."
and, much like the rest of that rambling, it contradicts itself.
the definition of viscosity is:
'resistance to flow'.
so, mr. lee's statement that: "... a classification 'that an oil will flow adequately"
is
"not a viscosity classification"
...is just another example of fun and colorful pedantry.
(Message edited by tramp on August 14, 2005) |
M1combat
| | Posted on Sunday, August 14, 2005 - 01:49 pm: |
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First... I think Mr. Lee pasted that. I don't think he wrote it (if I'm wrong, please correct me).
Second... The author made the point above your artfully clipped quote that the first number is only a relative number. Because of that, it can't exactly be used as a "viscosity" rating as such because it's relative to the second number. Or at least that's how I understood it. |
Brucelee
| | Posted on Sunday, August 14, 2005 - 02:52 pm: |
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I did paste that as an excerpt from "The Motor Oil Bible." I couldn't post a link since it this is a doc that is downloaded onto my system.
Sorry, I thought it was clear that was not me writing it.
(Message edited by brucelee on August 14, 2005) |
Jackbequick
| | Posted on Sunday, August 14, 2005 - 04:10 pm: |
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Here is a link to The Motor Oil Bible as a *.pdf file. The text in that matches up with what Brucelee posted so it is probably the same document his post was extracted from. I did not notice that it had the redundancies that were in the post above.
Let's all download it, read it carefully, and return here tomorrow for a written exam. :>
Jack
P.S. - I conducted a random drawing here and Tramp was chosen to write and administer the exam. |
Oldog
| | Posted on Sunday, August 14, 2005 - 04:33 pm: |
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Professor Trampus Violinnus 
exam :
Were there realy synthetic dinosaurs?
and for extra credit what do all of the letters on top of the oil bottle lable mean ....
 |
Light_keeper
| | Posted on Sunday, August 14, 2005 - 04:57 pm: |
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1. I think my son had some in his toy chest oh so many years ago.
2. They mean it's time to ask someone who knows if you have lots of time to listen. |
Tramp
| | Posted on Sunday, August 14, 2005 - 07:51 pm: |
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m1 "combat" said:
"Second... The author made the point above your artfully clipped quote that the first number is only a relative number. Because of that, it can't exactly be used as a "viscosity" rating as such because it's relative to the second number. Or at least that's how I understood it."
that's not how I understood it. and it wasn't that vague as to be prone to a lot of interpretation- let's revisit it, mr. combat: "it's not a viscosity classification"
hmmmmmmmmm...sounds rather definitive and absolute to me.
(Message edited by tramp on August 14, 2005) |
Jersey_thunder
| | Posted on Sunday, August 14, 2005 - 07:58 pm: |
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Impulse_101
"I use Redline 20W50 in my primary"
i was informed not to use redline in the primary...gums up the clutch plates...
you may want to look into that.
JT |
Tramp
| | Posted on Sunday, August 14, 2005 - 08:14 pm: |
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is there something heinously wrong with using sport-trans in it, like the manual says to? |
Steve_mackay
| | Posted on Sunday, August 14, 2005 - 08:36 pm: |
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Nope, nothin wrong with usin' SportTrans, but my S3T, my brother's S3T, and the Wife's Blast all shift better with Redline in the primary.
I don't use Redline 20-50, but 75W90 Redline synthetic gear gear lube. Haven't had a problem with gummed up clutch plates. |
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