Interesting TropArtic observation

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I was looking at the PDS on TropArtic Synthetic Blend PCMO and noticed something peculiar...

Cold Cranking Viscosity, cP:
5w30 = 5300 @ -30C
5W-20 = 3700 @ -30C
10W-30 = 3500 @ -25C

Why so much higher for the 5w30 and what does this mean in the real world?

BTW, I cannot find TA 5W-20 in any local Wal-Marts, only 5w30 and 10W-30...
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Well, if your part of the real world gets very, very cold, then it can matter alot. Notice also that the 10W30 is measured at a higher temperature. Those five degrees can be the the difference between liquid and solid.
 
quote:

Originally posted by GMorg:
Well, if your part of the real world gets very, very cold, then it can matter alot. Notice also that the 10W30 is measured at a higher temperature. Those five degrees can be the the difference between liquid and solid.

I don't think it's ever gotten to -30F around here...I remember back in '77-'78 it got to -22F one day, but usually it doesn't get below 0F here.

What unit of measure is "cP"? I know it measures CCA, but what unit is it? And why is 5w30 so much higher?
 
cp = centipose, a measure of oil's viscosity.
It has nothing to do with the battery's cranking rating .
At 0 deg F, the 5-20 and 5-30 will be about the same. That is the temp for measuring the first *5} number.
Things can go pretty wild below the standard measuring temp, as you can see.
 
I don't know about cold cranking temps, but i do know at 40*C and 100*C TropArtic is a bit thicker than some other oils. In addition their 5w30 and their 10w30 seem to be closer to one another than many other oil brands 5w30 and 10w30 are.

I like their products though. I've got TropArtic 5w30 in my crankcase as we speak.

As far as answering your question, i've read a great many PDS's and i've found many many mistakes on them. They are not always accurate. Perhaps the 3500 could really be 5300?
 
Actually Trop Artic looks to be thinner at cooler temps than many other oils, especially the 10w-30. At 40C, it's 66 Cst; most other dinos are 70 to 75 Cst. Lou, in regards to the CCS numbers, Trop Artic is fantastic, especially the 10w-30. Remember, 10W is measured at a higher temperature, so it may look "lower" or better than 5w30 which is measured 5 degrees centigrade cooler. Trop Artic has a CCS of 5300; Havoline is 5800. If the 10w-30 was measured at -30C, then it would likely crank about 7,000 to 8,000 Cp. The viscosity index of the Trop Artic oils is amazing too. Take a look at thisthread.
 
quote:

Originally posted by hominid7:
I don't know about cold cranking temps, but i do know at 40*C and 100*C TropArtic is a bit thicker than some other oils. In addition their 5w30 and their 10w30 seem to be closer to one another than many other oil brands 5w30 and 10w30 are.

Do you mean "thicker" in the sense that they have a higher viscosity at temperature (i.e. the cSt and SUS indexes) as compared to other oils of the same rated viscosity?

Yes, the 5W and 10W do seem to be close according to the (possibly inaccurate or sloppy) PDS. The exceptions are in cP and CCV, which seem to be higher at a statistically significant level.

I too have TA 5w30 in my Nissan 2.4L crankcase, and soon to have Motorcraft 5W-20 in my Dodge Caravan 3.3L, because I can't find the TA in 5W-20 around here...grrrrrr! (But I know the Motorcraft is a darn good oil...and only $9.xx per 5-gallon jug at WM).
 
With all the positive comments I've read about TropArtic, I wish there were more UOA's on it. I guess I'll have to be the next!
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quote:

Originally posted by LouDawg:
Do you mean "thicker" in the sense that they have a higher viscosity at temperature (i.e. the cSt and SUS indexes) as compared to other oils of the same rated viscosity?


Hey Dawg...Yes that's what i meant. Especially at 40*C the TA oil seems to be a bit thicker (higher vis) than many other 5w30's. That may be irrelevant though.

It seems to work well in my car though. Interestingly the oils ive used that my car seems to like (i know a car liking something is hard to quantify) are TropArtic/Motorcraft, Pennzoil, superflo, and Shell. All are relativly inexpensive when compared to the oils it didn't seem to "like". Those it didnt like being Valvoline (my old favorite for many years) and Castrol semi-synthetic, but i may give that another try soon.

I'm sure i change my oil so often that the type, grade, and brand are all likely non-important;)

[ May 23, 2006, 01:20 PM: Message edited by: hominid7 ]
 
quote:

Blue, are you sure about that?

Yep!
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I was commenting on 5W-20's & 5w30's in my post, no mention was made of 10W-30's.

A generic 5W-20 is blended from 4.5/5 cSt base oils plus VII.

A basic 5w30 formulation is 4.5/5 cSt plus some 6 cSt plus the VII.
 
quote:

Originally posted by Blue99:
..no mention was made of 10W-30's.

well, you quoted a comparison of 5W and 10W, so I naturally assumed that was the context for your comparative statement on 5w30. and you know what happens when we assume...
 
quote:

Originally posted by LouDawg:
I was looking at the PDS on TropArtic Synthetic Blend PCMO and noticed something peculiar...

Cold Cranking Viscosity, cP:
5w30 = 5300 @ -30C
5W-20 = 3700 @ -30C
10W-30 = 3500 @ -25C

mad.gif


This is really odd. When the Conoco/Philips/MC Synth blends first came out 1 1/2 years or so ago, the 5w30 cP was listed as 4500 on the manufacturer's data sheet. I probably don't have a hard copy of that sheet, but on a chart of oil viscosities that I made up at the time I list 4500 cP @ -30 C for the Philips 5w30 oil.
I don't think I made a mistake listing it either, because I clearly remember thinking that this was really good cP performance for an oil that competed costwise with dino 5w30 oils with cP ratings of 5500 to 5700 cP. Maybe the early Conoco/Philips cP number was in error.
Anyway, in the winter of 2004/2005 I used a 60/40 mix of MC 5w30/5W-20 - which I estimated had a cP of about 4100 - using the cP numbers listed for those oils at that time, which may have been in error. I never started my 2003 4.3L GMC at -30 C (-22 F) that winter, but at -15 F or so I could not tell any difference in cranking and starting than with the M1 5w30 that I used the previous winter. And the oil consumption on the MC mix was almost zero in 5000 mi vs. about 1 1/2 pints on the M1.
 
quote:

Originally posted by Ray H:
Another observation (whether or not it's "interesting" is subject to readers' personal interpretation...): I'm nearly 2,600 miles into my first interval with T/A 10W-30 and it's still difficult to see the oil film demarcation on the dipstick when I check the level. I'd always subscribed to the belief that oil that "dirties" quickly, is an oil whose detergent/dispersant package was doing its job properly. So, I'm wondering - does this T/A stuff have a weak detergent/dispersant package or is the base oil blend so stable under engine operation that it doesn't tax the detergent/dispersant package with partially oxidized oil molecule fragments to the degree we're accustomed to seeing with a conventional or syn-blend motor oil?

Nice logical analysis, however, I thought it was well established (and I think someone here even did a home science project) that different add packs will "darken" the oil more quickly under heat and thus "darkness" of the oil is a poor indicator of it's condition/performance.
 
quote:

Originally posted by sky jumper:

quote:

Originally posted by Ray H:
Another observation (whether or not it's "interesting" is subject to readers' personal interpretation...): I'm nearly 2,600 miles into my first interval with T/A 10W-30 and it's still difficult to see the oil film demarcation on the dipstick when I check the level. I'd always subscribed to the belief that oil that "dirties" quickly, is an oil whose detergent/dispersant package was doing its job properly. So, I'm wondering - does this T/A stuff have a weak detergent/dispersant package or is the base oil blend so stable under engine operation that it doesn't tax the detergent/dispersant package with partially oxidized oil molecule fragments to the degree we're accustomed to seeing with a conventional or syn-blend motor oil? Opinions invited. (Just remember what they say about "opinions"...
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)


I'd say weak add pack. the last time my oil stayed that clean was on ST syn, with has weak add pack. GC got dirty real quick.


Should I be concerned then? For the most part, TA seems to be getting rave reviews, but what about this weak add-pack concern? My oil after about 1500 miles is also still pretty clean. Could it be that the engine just isn't that dirty inside and therefore the add-pack may be fine but there isn't much to clean? (It's a Nissan 2.4L DOHC with 37K miles on it.) Anyone else notice the TA "clean oil" phenomenon?
dunno.gif
 
quote:

Originally posted by Blue99:

quote:

What unit of measure is "cP"?

The conversion is:

Centistokes x specific gravity = Centipoise

Note: Use .86 for the specific gravity as a good ball park number.
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So then I assume (maybe incorrectly) that:
==========================================
A. Centistokes = cSt = one of the two uom's for viscosity (the other one being SUS), measured at 40C and 100C on a typical PDS

If so, and as mechtech said:
============================
B. Centipose = cP = the uom for cold cranking viscosity (CCS?)

And then as you said:
======================
C. cP = cSt x s.g.

If all of these are true and my first assumption about cSt is correct, the I come to the following two conclusions:
=========================================
1. The s.g. for the TA 5w30 is 0.828
2. The PDS for 10W-30 is a typo/misprint and should be more like 5500.

Am I wrong? Just doing a little math here...
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Mass paranoia has struck again! Have no fear here. What 427Z06 said is correct. I'm one of the people who tested many brands of oil (not for this purpose but this was observed anyway). Not that holding a lot of crud in suspension doesn't darken oil - surely suspended particles will darken an oil. It's because several factors affect used oil color that you can't look at the color of used oil and say it's only because of such and such without having more information to base it on.
 
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