HTHS data question

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I have a question as to the comparison of data gathered using test method ASTM D4741 against data gathered using ASTM D4683.
I like to compare data.....but I start asking questions when the data is gathered using different test methods.
I looked at the ASTM website....and they are different methods.....but I don't know if the comparison between the 2 data methods would be valid.
Of course..I understand......like the "base oil" factor.....this is only 1 specification of a motor oil.....not the all deciding factor.

Today, I visited the websites for the oils listed below.....and gathered this data.
I only looked at 5W-20 and 5W-30 oils....
Royal Purple did NOT list the HTHS value
Motorcraft did NOT list the ASTM method
Redline used ASTM D4741 method
The others used ASTM D4683

5W-20
Redline 3.3
Mobil 1 2.62
Mobil 1 EP 2.7
Pennzoil Platinumn 2.6
Motorcraft syn/blend 2.65
Amsoil XLF 2.7

5W-30
Redline 3.8
Mobil 1 3.09
Mobil 1 EP 3.1
Pennzoil Platinumn 3.1
Motorcraft syn/blend 3.2
Amsoil XLF 3.2
Amsoil ASL 3.2
 
Castrol Syntec is 2.92.

Minimum for 15W-40 is 3.5, minimum for 10W-40 and lower is 2.9.

Minimum for ACEA A3 is 3.5.

Minimum for 30 weight oils is 2.9. Minimum for 20 weights is 2.6.

Lower typically means better fuel economy higher typically means more "robust" protection.
 
http://www.bobistheoilguy.com/forums/ubb...true#Post959395
First read that, then hear my opinion out if you want. Redline's HTHS seem too high to be believable considering their kinematic viscosities at 100C. HTHS tests were developed because multigrade oils have temporary shear thinning so the HTHS viscosities do not correlate to the kinematic viscosities with just a constant. All but one grade of Redline street oils are said to be straight weight oils. Compare other straight weight motor oil HTHS viscosities with Redline's...that is, take the ratio of KV@100C to HTHS viscosities. Not comparable when I did it last. Additive effects exist but could it explain the difference? I don't think so.
 
Posted Feb 3, 2005, in the HTHS thread in the "Question of the Day" forum:
Originally Posted By: MolaKule
Good Question:

Here is the actual wording from paragraph 14.6 "Relative Bias" of D4741-00:


Results from this test method were found, by interlaboratory studies to agree with those from Test Method D 4683 at both 100 C and 150 C. They can be expected to give, on average in the long run, the same results for the same oil. D4683 says the same thing in paragraph 14.3 but adds another that correlation is the same with test method D5481 as well.

No deltas were given for D4683 verses D4741 or D5481.
 
The ASTM D 4683 is the older method (2004), and also is refered to as the TBS (tapered bearing simulator) method.

The ASTM D 4741 is newer (2006), and is also known as the TPV method (tapered plug viscometer). This method is also known as CEC-L-36-A-90 and is the test specified by the ACEA.

The results of both test are very similar, with the 4741 being signifcantly mor repeatable and slightly more reproducible. The 4683 values tend to be slightly higher (0.02 or so)

Both methods (along with ASTM DS481) are acceptable for determing HTHS for the SAE J300 viscosity grade criteria.
 
SORRY!....I should have searched this......
I even remember reading it at the time......
sorry for the duplication.
However....Thank you JPR for the explaination......I had read the ASTM description but your "Repeatability" and further description is great information for me.
 
Last edited:
Originally Posted By: JAG
Additive effects exist but could it explain the difference? I don't think so.

Does that leave only the two obvious possibilities of:

1) Base oil effects; or

2) Test inconsistency between brands?
 
If you go for a lower HTHS rating at 150C for increased fuel economy do you worry about lack of abrasion resistance because of the lack of zinc dithiophosphate mandated by current standards? And have you ever wondered how these new Xw-20 weight oils get such solid HTHS numbers considering their kinematic⁢ ⁢viscosity⁢ ⁢at⁢ ⁢100C? There is no direct connection or a constant to relate kinematic⁢ ⁢viscosity⁢ ⁢at 100C and HTHS numbers at 150C so it must be additives, different ones for all the different brands and different ones again for viscosities within the same brand. Kind of makes this new anti-friction improve gas mileage additive market look like a shot in the dark by a blind man for the poor sucker that buys these things and pours them in the crankcase especially the guy that reads the HTHS values on a data sheet for the stuff he pours in his own engine. Gotta know the numbers or you might make the wrong choice.
 
Originally Posted By: BarkerMan
There is no direct connection or a constant to relate kinematic⁢ ⁢viscosity⁢ ⁢at 100C and HTHS numbers at 150C so it must be additives, different ones for all the different brands and different ones again for viscosities within the same brand.


I can't follow your logic here. It sounds like you are saying that kinematic viscosity and HTHS viscosity are not correlated perfectly and then concluding that the lack of correlation is based on differences in additives. Why could it not depend on differences in base oils, particularly Red Line's base oils vs. others, since that is where the largest difference (or discrepancy) seems to exist?

The only additive difference that would possibly explain it as far as I know would be VIIs and I have been of the understanding that many Grp IV/V oils do not use them at all, including all but one Red Line grade and at least some M1 grades; and that many others use very little.
 
That's kind of the thought, glennc. The additives can get in the way, not help out. And when you get around to VII's it means that the HTHS values are different when the oil has been used for a while. Sometimes it's important to follow an HTHS value curve as the oil gets run. What makes Red Line a good shot for high performance is that it's HTHS life curve while surviving in a real engines is better than anything we have tested, not by a little bit but by a margin that make you think that Roy Howell and his group got it right. After running down the road many Xw-20 weight oils will have the same HTHS numbers as a Xw-30/40. That's why a Cop in West Texas with a Crown Vic idling for hours under a tree in 100F weather with the A/C on can still catch a speeder going 100 mph and run 5w-20 oil. In other words HTHS after a few miles is just as important as the starting numbers.
 
BarkerMan, does your data match the commonly seen Red Line chart of viscosity/shear rate, shown in the following link? (Sorry, can't find a larger image of the chart.)

http://redlineoil.com/whitePaper/motoroils.pdf

It would be interesting if you have verified this independently. This is one area where Red Line's rather striking claims for its products' performance have caused people to question the claim itself.
 
Independent tests results would be quite interesting, but in the meantime I don't know of any reason not to take Redline's HTHS statements at face value. But the two interesting follow-up questions are how they do it and are they any side-effects.

In regards to how they do it, I'd guess the Redline's high moly levels play a key role. There's likely more to it than that, but the difference is certain to be in the additive package rather than the base oil.

As far as side effects go, higher sulfated ash levels and particulate emmisions are the most likely suspects, but not the only ones. But at the bottom line, how significant they are almost certainly depends upon the details of the application.
 
The guy that runs that lab says Red Line numbers are good. Differences are not statistically significant. Other people involved in engine programs tell me those HTHS numbers are good too. What they chase is the degradation curves taking samples during track testing and this is where Red Line is reported to do well. Everyone in the dyno shop uses Red Line in their street cars, high performance or not. They see lots of different engine oil and get offers to use other brands for free and they pay for Red Line. They all say they do not know if it's the best oil but they know how it works and it's good enough for the job. Their opinions probably have nothing to do with the average daily driver because even though they use it in daily drivers with good results they like it because it performs when stressed. As a side note they use Red Line 5w-20 in cars spec'd for anything from Xw-20 to Xw-40 and that includes a Z06 that does a lot of track days and commuting.
 
Originally Posted By: jpr
Independent tests results would be quite interesting, but in the meantime I don't know of any reason not to take Redline's HTHS statements at face value.

Did what I say make no sense? Calculate the ratio of KV@100C to HTHS for Redline. Do same for other straight weight oils and non-straight weight oils. Do it for other high ester content motor oils like Silkolene and Motul 300V. See how the data compares. I'd do it and post it but am too busy today. I did calculate the ratio for pure 8 cst PAO from XOM and it was 3.1. That's like a straight weight oil without any additives so the ratio is on the low end. Having VIIs makes the ratio increase because they increase kinematic viscosity more so, percent wise, than HTHS. Oils like Mobil 1 0W-40 have ratios on the high end due to high VII content.

As a note, when oils are permanently sheared, the percent change in HTHS is about 1/2 the % change in kinematic viscosity at 100C. This is from a study done in the 1980's.
 
It can be included, just pay for it. A lot of places that do UOA's don't have the equipment to do it. In fact a lot of these labs are not ISO9000 certified and have no plans to expand their services to include such tests.
 
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