Well sir, it may speak for itself to a well seasoned veteran such as yourself, but I have no idea whasoever what it means
TIA,
Robert
Virgin Mobil Delvac 1 Synthetic 5W-40 API CH-4/SJ
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TIA,
Robert
Patman
Staff member
When it comes to HTHS numbers, the higher the better. A higher number means the oil doesn't thin out as much at extremely hot temps (150c).
Patman, it's not just a test of vis at hi temp, but the oil is mechanically sheared as well—either with the Bosch injector method or the ASTM D4741 method. The purpose of these tests is to simulate the conditions of highly loaded bearings in a "real" engine and how the oil would "behave" under those conditions.
[ January 23, 2003, 11:24 AM: Message edited by: G-Man II ]
There is also a ASTM D 4683 method that shows the new Pennzoil 5/20 at 2.65. Put that in a hotrod with alot of nose pressure on the flat tappet cam be-it hydraulic or solid and run it! Scary huh?
[ January 23, 2003, 12:35 PM: Message edited by: dragboat ]
[ January 23, 2003, 12:35 PM: Message edited by: dragboat ]
G-ManII,
Forget about the bosch shear stability test results ...that is a simple bench test that doesn't really analog what goes on in a motor. Look at the results of the M1, 0w-40 in the API, SJ Sequence IIIE test - they are shown in that same SAE paper. This test ALWAYS results in oxidative thickening - but the M1, 0w-40 thinned out by 20% in the single length test and 15% in the double length test. There was more thickening in the double length test from oxidation, so this offset some of the polymer shearing. Compare the test results of the Mobil 1, 0w-30 and 0w-40 and you'll clearly see the 0w-30 is the more shear stable grade, as I'd expect.
There is only so much you can do even with the best PAO/Ester blends ....Amsoil makes a 0w-40 that has a VI of 201. I haven't tested it after extended use, but I am quite certain it will also shear somewhat. This is why I've never been a big fan of these 0w-40/5w-50/10w-60, "One size fits all" synthetic lubes for long drain intervals. It is a very appealing concept for someone who lives where there are sizable temp swings, but it is rarely the best solution in terms of optimized, extreme temp properties.
Finally, you'll note the recent oil analysis result of the 0w-40 in a 1.8L, VW turbo, where it thinned out to a 30wt oil in 6000 miles. No surprise at all, given the formulation chemistry ....
TooSlick
Forget about the bosch shear stability test results ...that is a simple bench test that doesn't really analog what goes on in a motor. Look at the results of the M1, 0w-40 in the API, SJ Sequence IIIE test - they are shown in that same SAE paper. This test ALWAYS results in oxidative thickening - but the M1, 0w-40 thinned out by 20% in the single length test and 15% in the double length test. There was more thickening in the double length test from oxidation, so this offset some of the polymer shearing. Compare the test results of the Mobil 1, 0w-30 and 0w-40 and you'll clearly see the 0w-30 is the more shear stable grade, as I'd expect.
There is only so much you can do even with the best PAO/Ester blends ....Amsoil makes a 0w-40 that has a VI of 201. I haven't tested it after extended use, but I am quite certain it will also shear somewhat. This is why I've never been a big fan of these 0w-40/5w-50/10w-60, "One size fits all" synthetic lubes for long drain intervals. It is a very appealing concept for someone who lives where there are sizable temp swings, but it is rarely the best solution in terms of optimized, extreme temp properties.
Finally, you'll note the recent oil analysis result of the 0w-40 in a 1.8L, VW turbo, where it thinned out to a 30wt oil in 6000 miles. No surprise at all, given the formulation chemistry ....
TooSlick
In looking at the SAE paper, I see your point about the 0w40's performance on the extended Sequence IIIE test. But as far as the Bosch injector test for shearing just being a "bench test," the other industry standard test which gives the HT/HS numbers (ASTM D4741) is a bench test, too, is it not?
AL, did you get those numbers on DELVAC-1? I'm ready to get it for the summer haul of 6k miles in my E-150 van with 4.2L six. With all the positive talk about D1, thereis little evidence around here.The truckers must know something.
Ron
Ron
Well I love these academic discussion because it allows me to learn. With that said the only way to prove or disprove it is to do a field trial! Try the 0W40 for 6000 miles and test it. Then try try Delvac1 for 6000 miles and test! I know this sounds silly but real world field trials often prove to be a better indicator then lab tests.
Yup, up to I believe 21%.
And not only that, I have noticed in my own experiences, that the lab tech that does the tests has a part in it also. For instance, I notice when one guy does the tests, that the numbers are always on the higher side, and another tech his are on the lower side, and another guy seems to always be on both sides of the fence.
And not only that, I have noticed in my own experiences, that the lab tech that does the tests has a part in it also. For instance, I notice when one guy does the tests, that the numbers are always on the higher side, and another tech his are on the lower side, and another guy seems to always be on both sides of the fence.
Hi,
yes, in my recent UOA here through the ExxonMobil lab a similar situation evolved
There is indeed a variance margin on a VOA's content
ExxonMobil computerise the VOA parameters - these are adjusted by the Chief Lubricants Engineer to "warning", "action" etc. alert loadings
They use the latest formulation as the base so
old formulation stocks can be "wrongly" assigned a warning etc. if a UOA is outside the latest formulation's settings.
It is all in the intellectual interpretation then - this should be based on experience and past results - looking for "spikes" and irregularities etc
Over the last 20 odd years I have had to challenge UOA results many many times from Oil Company Labs. Usually the Oil Company will err on the cautious side - but mostly it is technician inexperience that creates the problem. If the Lab technician is "clinical" and has no knowledge of interpreting the results they may be dispatched with "errors" included
Regards
yes, in my recent UOA here through the ExxonMobil lab a similar situation evolved
There is indeed a variance margin on a VOA's content
ExxonMobil computerise the VOA parameters - these are adjusted by the Chief Lubricants Engineer to "warning", "action" etc. alert loadings
They use the latest formulation as the base so
old formulation stocks can be "wrongly" assigned a warning etc. if a UOA is outside the latest formulation's settings.
It is all in the intellectual interpretation then - this should be based on experience and past results - looking for "spikes" and irregularities etc
Over the last 20 odd years I have had to challenge UOA results many many times from Oil Company Labs. Usually the Oil Company will err on the cautious side - but mostly it is technician inexperience that creates the problem. If the Lab technician is "clinical" and has no knowledge of interpreting the results they may be dispatched with "errors" included
Regards
GMan II,
The high temp/high shear test does not show how much the oil will permanently shear in actual service. It is more an indication of the # of polymeric thickener in the formulation. The HT/HS test causes temporary shearing as the oil flows through a tapered bearing simulator and "bounces" back to its original viscosity as it exits the restricted channel in the test setup. A good analogy would be taking a piece of rubber and running it through some tightly spaced rollers. The rubber would stretch and thin out as it passed though these rollers, but return to it's original thickness on the other side, as long as you'd didn't exceed the elastic limit of the material. To carry this analogy further, permanent shearing is more akin to plastic deformation, where the material yields and cannot return to it's virgin state.
What is happening in the HT/HS test is that the long chain polymers that make up the Viscosity Index Modifier, tend to align themselves in the direction of flow, which causes the oil to thin as it is squeezed through this bearing simulator.
The results of engine sequence tests are a much better indicator of how shear stable the oil will be in actual service than any bench test ....This is clearly the case with the Mobil 1, 0w-40.
Happy Holidays!
Tooslick
Dixie Synthetics
The high temp/high shear test does not show how much the oil will permanently shear in actual service. It is more an indication of the # of polymeric thickener in the formulation. The HT/HS test causes temporary shearing as the oil flows through a tapered bearing simulator and "bounces" back to its original viscosity as it exits the restricted channel in the test setup. A good analogy would be taking a piece of rubber and running it through some tightly spaced rollers. The rubber would stretch and thin out as it passed though these rollers, but return to it's original thickness on the other side, as long as you'd didn't exceed the elastic limit of the material. To carry this analogy further, permanent shearing is more akin to plastic deformation, where the material yields and cannot return to it's virgin state.
What is happening in the HT/HS test is that the long chain polymers that make up the Viscosity Index Modifier, tend to align themselves in the direction of flow, which causes the oil to thin as it is squeezed through this bearing simulator.
The results of engine sequence tests are a much better indicator of how shear stable the oil will be in actual service than any bench test ....This is clearly the case with the Mobil 1, 0w-40.
Happy Holidays!
Tooslick
Dixie Synthetics
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