Updated VII content and base-oil-and-DI viscosity at 150 °C estimate spreadsheet

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Boxnuts and I were discussing the density correction factor in my spreadsheet for the VII content, which is effectively equivalent to the A_Harman index, and base-oil viscosity at 150 °C (BO DV150 = HTFS), which is the full-shear viscosity of an oil at 150 °C (as opposed to the high-shear viscosity HTHS), with only the base oil and detergent - inhibitor (DI) package contributing to the viscosity, with the VII molecules fully aligned with the flow because of the extreme shear rate and not contributing to the viscosity at all, such as in the valvetrain.

There was data for 17 15W-40 test oils with different VIIs and base oils in the Hugh Spikes paper. The average density correction factor for those turned out to be 0.898.

While I was calculating that, I also calculated the error in the ASTM D341 extrapolation to get KV150, which is used for the A_Harman index (effective VII content), which is in turn needed to calculate the base-oil viscosity at 150 °C.

I have now fully verified the validity of both the A_Harman index and base-oil viscosity at 150 °C calculations by accounting for the errors in the density correction factor and ASTM D341. Previously I had verified the validity by comparing against the test oils but without validating the ASTM D341 and density correction factor. So, now, we know that all the calculations are valid.

One exception is the PMA VII -- the A_Harman index and base-oil viscosity at 150 °C calculations don't work with this seldom-used VII type. This VII is seldom used these days because of the high solid-polymer content causing deposits.

I have now set the density correction factor to 0.917. While this is larger than the actual average of 0.898, it accounts for the ASTM D341 routinely underestimating KV150 in the presence of a VII. Therefore, it improves the accuracy and reliability of the calculations.

The previously used density correction factor was 0.905. The only effect of the change is to increase the VII content and decrease the base-oil viscosity at 150 °C for all oils, without changing the order of the oils in either quantity.

The biggest changes occur for oils with little or no VII. For example Amsoil ACD 10W-30/SAE 30 had 0.0% VII before, but now, it has 0.64% VII. While Amsoil claims it to be VII-free, it could have mPAO, which shears like a VII. In fact mPAO can be considered to be a type of VII. Of course, it could also be the result of the various approximations made. Likewise Valvoline Advanced Synthetic 5W-20 was estimated to be almost a monograde, but now, it's estimated to have a small amount of 0.88% VII.

You can read the full discussion here.

Verification of the density correction factor and ASTM D341 against the Hugh Spikes test oils

Finally here is the updated spreadsheet. Click on the link for the Google sheet, which you can download. As I said before, the calculation isn't expected to work for a PMA VII. Note that the base-oil (full-shear) viscosity (BO DV150 = HTFS) refers to the combined viscosity of the base oil and additive package (detergent - inhibitor (DI) package) excluding the VII. Moreover, the VII content is only an effective number equivalent to the A_Harman index, which measures the temporary shear, and it corresponds neither to the actual solid-polymer VII content nor to the content of a solid polymer packaged in a base-oil solvent.

Estimated VII content and BO DV150 (base-oil viscosity at 150 °C = HTFS) of selected oils

[Linked Image from lh3.googleusercontent.com]
 
Thanks, great info. I like the VAS 5w20 and M1 AP 5w20 in terms of low VII's.
 
Originally Posted by LeoStrop
Thanks Gokhan!

On this recent thread, @edyvw mentions the new Motul 8100 X-clean+ 5W-30, wich looks good in terms of low VII's also.

https://d23zpyj32c5wn3.cloudfront.n...100_X-Clean__5W30_0612_PT.pdf?1492017083

You're welcome.

I've now updated the spreadsheet to include the Motul 8100 X-clean+ 5W-30 (after extrapolating the density from 68 °F to 60 °F). Indeed it has a record-thick base oil for a 5W-30 -- 3.0 cP at 150 °C without the VII -- with a low VII content on top of that, which raises the HTHS to 3.6 cP.
 
Originally Posted by RDY4WAR
Here's one you can have fun with. They're the new site sponsor also. Notice that the 5w-20 HTHS is higher than the SAE 20 HTHS despite having the same KV100. Also note their 10w-40 vs SAE 40.

https://www.hplubricants.com/wp/wp-content/uploads/2020/04/HD-Engine-Oil-PDS.pdf

The VII certainly raises the HTHS -- that's one of its functions. You can make a 5W-20 with little or no VII.

POE apparently temporarily shears quite a bit (POE shear study). This could be why their monogrades seem to behave like they effectively have a small amount of VII. Of course, there could be some errors in ASTM D341 and density extrapolation as well. The only way to find out these errors would be to get the low-shear dynamic viscosity at 150 °C (DV150) from them. Their SAE 20 monograde could have a high-molecular-weight POE, which would temporarily shear quite a bit.
 
Originally Posted by Gokhan
I've now updated the spreadsheet to include the Motul 8100 X-clean+ 5W-30 (after extrapolating the density from 68 °F to 60 °F). Indeed it has a record-thick base oil for a 5W-30 -- 3.0 cP at 150 °C without the VII -- with a low VII content on top of that, which raises the HTHS to 3.6 cP.


Do you actually have a way to measure this? I've got 20L of it sitting on the shelf and would be happy to send a Blackstone-sized sample for evaluation. PM me if you can make it happen.
 
Originally Posted by SubieRubyRoo
Do you actually have a way to measure this? I've got 20L of it sitting on the shelf and would be happy to send a Blackstone-sized sample for evaluation. PM me if you can make it happen.

No, you need a very advanced device to measure the full-shear viscosity, as the shear rates are extreme. It wasn't possible until a couple of years ago, and that's when the Hugh Spikes group measured it and wrote two papers on it, which I discussed in the white-papers section under full-shear viscosity.
 
Originally Posted by Gokhan
Originally Posted by RDY4WAR
Here's one you can have fun with. They're the new site sponsor also. Notice that the 5w-20 HTHS is higher than the SAE 20 HTHS despite having the same KV100. Also note their 10w-40 vs SAE 40.

https://www.hplubricants.com/wp/wp-content/uploads/2020/04/HD-Engine-Oil-PDS.pdf

The VII certainly raises the HTHS -- that's one of its functions. You can make a 5W-20 with little or no VII.

POE apparently temporarily shears quite a bit (POE shear study). This could be why their monogrades seem to behave like they effectively have a small amount of VII. Of course, there could be some errors in ASTM D341 and density extrapolation as well. The only way to find out these errors would be to get the low-shear dynamic viscosity at 150 °C (DV150) from them. Their SAE 20 monograde could have a high-molecular-weight POE, which would temporarily shear quite a bit.


The ester concentration is uniform across the board.
 
Originally Posted by RDY4WAR
The ester concentration is uniform across the board.

Yes, the calculation is indeed showing unaccounted shear uniformly across the board, likely stemming from the ester. However, we can't rule out the ASTM D341 extrapolation overestimating the viscosity without having actual low-shear DV150 (or at least KV150) data.
 
Can someone tell me what's so special about the HPL Oil (example 5W-30) besides the price?
I made a comparison to QS UD 5W-30 and to me the QS looks better, not to mention price which is much lower.
Is there something else that I don't know about that it justifies such a high price?
[Linked Image]


HPQS.jpg
 
based on chart, if one product have higher VII, does it bad? will the lubricants won't stand of high shear in the long run?
 
Can someone tell me what's so special about the HPL Oil (example 5W-30) besides the price?
I made a comparison to QS UD 5W-30 and to me the QS looks better, not to mention price which is much lower.
Is there something else that I don't know about that it justifies such a high price?
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View attachment 23721

They are in different categories, the quaker state is unuseable in >3.5 cP HTHS applications. If you don't need that, the QS definitely is better value.
 
Can someone tell me what's so special about the HPL Oil (example 5W-30) besides the price?
I made a comparison to QS UD 5W-30 and to me the QS looks better, not to mention price which is much lower.
Is there something else that I don't know about that it justifies such a high price?
[Linked Image]


View attachment 23721
What is it you are comparing beyond price ?

These are two entirely different motor oils.

Would you honestly expect Quaker State to hold up to rigorous testing as well as HPL ?

What we have here is a shining example of you get what you pay for.

For more enlightenment see Gokhan, A_Harman, MolaKule et al posts, or read Lex's 1000 page treatise on esters.

Signed,
a happy user of HPL HDMO 0W16, 24 quarts, idk, ~80k miles...and I did not even extend the OCIs beyond 12k miles. Heck, I could have confidently doubled that OCI for greatest ROI.
 
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