-81°F, I think is bogus for GC

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This is the company that brought us the term"GroupIII Synthetic".
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'nuff said,
Mark
 
quote:

Originally posted by G-Man II:
I don't think anything is amiss. What I do think is that at extreme temps like -81°F these calculations are meaningless (and are probably not even accuarate). cSt vis is meant to be a measure of a HOT oil's viscosity. The viscosity index was never meant to indicate an oil's resistence to thickening at cold temps; it was meant to show an oil's ability to resist THINNING at high temps, with 40°C as the established baseline, and 100°C as the upper limit. These were considered the operational parameters of a motor oil back when the concept of VI was first developed (which was in the late 1920s, I believe).

Cold vis is calculated and measured differently and is reflected in the cold cranking viscosity number, which is measured by ASTM D-2602, and gives the "apparent" vis of the oil at low temps. The measurement unit is in centipose (cP).

As an example of how two oils with identical VIs, which are the same viscostiy at higher temps, can behave very differently at colder temps, take a look at this page comparing a VHVI base oil to PAO.


VI is a standard measure of the rate of change of viscosity to temperature. The higher the VI, the lower the rate of change. Kinematic viscosity is the viscosity that we're interested in when talking about pour point. Kinematic viscosity is measured under the flow of gravity (i.e. very low shear rates) as is pour point. Dynamic viscosity (the viscosity that you're link refers to) is a different property altogether. It's kinematic viscosity times density and is used to measure viscosity at high shear rates.

I already pointed out that Amsoil's 0w-30 is considered "frozen" at 39,800cSt. Let's look at some other oils:

Pennzoil Multigrade 5w-30 is "frozen" at 35,860cSt.

Pennzoil Multigrade 10-40 is "frozen" at 32,800cSt.

Mobil 1 5w-30 is "frozen" at 39,100 cSt.

So these oils are considered frozen when their kinematic viscosity is ~32,000cSt to ~40,000cSt. Again, the German Castrol is about 40,000cSt at -50F. This is a respectable and believable pour point that fits in with it's other cold temperature specs.

The thread-starter is right. GC-s pp is simply wrong.
 
This whole debate can easily be settled. Many grocery stores sell dry ice and I have measured it to be past -80º F. Simply take some oil, put it in a metal container and pack it in the dry ice with a thermocouple attached to a meter and see if it is still fluid at -80º F.

I've put it in my freezer before at 0º F and it seemed to react just like every other synthetic oil. It thickens noticeably but still sloshes in the glass.

I think I'm going to perform this test this weekend. I have a entire freezer of dry ice at my work and I even have some good old liquid nitrogen if the dry ice doesn't do the trick. I'll go to Autozone and plunk down my $4.99 and get a bottle of the magic "schmierstoff" and turn it into a solid green gummi bear.

I'll report back Sunday evening.
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Jay, where are you getting these "frozen" figures for oils from?

And until I see proof otherwise, I'll assume that based on the industry standard tests used, the pour points listed for any oil on the manufactuer's data sheet is valid and accurate—no matter how "unbelievable" any particular one may seem.
 
quote:

Originally posted by Patman:

quote:

Originally posted by Tim H.:
OK, weather it peforms at cold is one thing, and hot is another. but what is it going to look like at 5000 miles?

Like this (from my sister's 99 Civic):

code:



Mobil 1 5w30 Castrol 0w30

8000 miles 5500 miles

.

Iron 19 14

Lead 10 4.5

Aluminum 5.2 2.5

Copper 3.8 3.0

Silicon 8 11

Nickel 0.1 0

Chromium 3 0.8

Titanium 0.1 0

Tin 0.2 0

Silver 0.4 0.2

Vanadium 0.2 0

Potassium 0 0

Sodium 6.5 1.5

Boron 118 16

Barium 0 0.1

Manganese 226 149

Calcium 2834 3003

Magnesium 50 129

Moly 82 15

Phosphorus 902 781

Zinc 1091 998

Fuel 0 0

Glycol 0 0

Water 0 0

Sulfation 49% 23%

Oxidation 51% 29%

Nitration 37% 21%

VI 174 182

Vis @ 40c 50.6 62.1

Vis @ 100c 9.5 11.5

TBN (D4739) 5.27 6.90



'Nuff Said!!!!
 
Kemopro diester/ester 5w30 has a pour point of -75F. Synergen/Redline have oils that pour @ -65F.
Someone already mentioned Neo/Delo... How about all those other boutique/foreign/motorcycle/race oils out there?

My only question is: If it is -80F outside, would you even bother trying to start your car without an oilpan heater? block coolant heater? heated garage?

I can only imagine the stress put on the engine and oil pump trying to pump oil that pours like marshmallow fluff.

What is the definition of pour point? Is is anything like synthetic oil-- Definition to be provided by each independent marketeer!
 
quote:

Originally posted by GROUCHO MARX:
Does the fact that the M1 interval was 45% longer mean anything?

Not when the question was "but what is it going to look like at 5000 miles?"
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quote:

'Nuff Said!!!!

Its' not really a fair comparison. For one, M1 has been tweaked. I'm not saying the GC isn't as good or won't be better, but you can't base much off of one UOA, as the Redline lovers will tell you.
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OK OK GC is the BEST oil ever.

But why are my 20,000 mile results about the same as above? Plain vanilla Amsoil ASL 5W-30 . $4.50 qt. Order today, arrive tomorrow.

Funniest thing? People gripe about Amsoil availability. I have NEVER seen a bottle of GC.

'nuff said. I'm going back to my cave.

[ September 06, 2003, 05:18 PM: Message edited by: Pablo ]
 
quote:

Originally posted by G-Man II:
Jay, where are you getting these "frozen" figures for oils from?

And until I see proof otherwise, I'll assume that based on the industry standard tests used, the pour points listed for any oil on the manufactuer's data sheet is valid and accurate—no matter how "unbelievable" any particular one may seem.


G-man, I just picked some oil specs at random and used the viscosity calculator that I posted earlier to calculate the kinematic viscosity at their pour points.

I found this in, "Lubrication Fundamentals":
quote:


...it is necessary to have some method of determining the viscosities of lubricating oils at temperatures other than those at which they are measured. This is usually accomplished by measuring the viscosity at two temperatures, then plotting these points on special viscosity-temperature charts developed by ASTM. A straight lined can then be drawn through the points and viscosities at other temperatures read from it with reasonable accuracy...The line should not be extended below the pour point or above approximately 300 deg F since in these regions it may no longer be straight.

So the viscosity calculator is a legitimate way of calculating Kvis from pour point to about 300 deg F.

It's interesting that the kvisosities of the dino oils are lower at their pp's than the synthetic oils. This is because of the wax in the dino oils. Their pp's are wax limited and the synthetic oils are viscosity limited.
 
quote:

OK OK GC is the BEST oil ever.

But why are my 20,000 mile results about the same as above? Plain vanilla Amsoil ASL 5W-30 . $4.50 qt. Order today, arrive tomorrow.

Funniest thing? People gripe about Amsoil availability. I have NEVER seen a bottle of GC.

'nuff said. I'm going back to my cave.

I'm with Pablo on this one. People are making to much of a big deal of this GC. I can order Amsoil or buy M1 and get great results. I won't have to wonder around the country looking for it either. And lets see the GC match Pablo's results!!!
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And I still think Amsoil 30wts are A3 rated!!

[ September 06, 2003, 05:35 PM: Message edited by: buster ]
 
Socialist Canadians are deprived, what can I say.
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Your taxes are so high that oil costs $10qt.
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Just joking. Nice country.
 
OK, I am convinced. The Red Line 5W30 is going in my lawn mowers and the German Castrol is going to have to be relegated to getting the groceries. Ops, sorry, can't find the "Green Stuff". Guess I'll just go on as before.

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quote:

Originally posted by GROUCHO MARX:
Does the fact that the M1 interval was 45% longer mean anything?

Just asking.


It's not really a direct comparison between M1 and GC because of the mileage difference, but do look at the data of GC on it's own, for a 5500 mile run it looks very good, especially since that was the first run with this oil. The TBN is still very strong, and it's on the lower scale too, and oxidation/nitration are good (and will go down with the second interval)
 
quote:

Originally posted by Pablo:
OK OK GC is the BEST oil ever.

But why are my 20,000 mile results about the same as above? Plain vanilla Amsoil ASL 5W-30 . $4.50 qt. Order today, arrive tomorrow.

Funniest thing? People gripe about Amsoil availability. I have NEVER seen a bottle of GC.

'nuff said. I'm going back to my cave.


Amsoil is definitely one of the best oils out there, I recommend it to my US friends with LS1s and LT1s all the time. But here in Canada, it's easier for my friends to pop into Walmart, or Canadian Tire, and pay $6.29 to $6.66 per liter for GC than it is to try and find an Amsoil dealer, and pay $9 to $10 per quart. Even when I used to be an Amsoil dealer myself, I paid more for Amsoil at my cost than Mobil 1 was selling for at Walmart! So it's a hard sell up here based on that. I only know one guy in my car club who uses Amsoil. Most of the rest use Mobil 1, but one or two have started buying GC.
 
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