Density and HTHS

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There seems to be a missing link when comparing engine oils containing VII/VMs in escalating treatment levels with each other and to mono-grade engine oils.

Mono-grade engine oils as a group, have higher densities than the above mentioned conventional VII/VM containing multi-grade engine oils.

The mono-grades, as a group have higher HTHS for a given KV100 specification than VII/VM containing engine oils.

When comparing VII/VM conventional multi-grades with each other, the densities go down with increased viscosity grade spread,
which could be attributed to higher VII/VM treatment levels.

With the resulting density being lower from the VII/VMs, the relationship between KV100 and HTHS suffers.

Often when comparing a series of multi-grade engine oils from a manufacture, for example brand XYZ 0W20, 0W30 and 0w40 will have descending densities, along with corresponding worsened KV100 vs. HTHS values.

Is there an explanation for the non-linear relationship between density, VI and HTHS?

Another stumbling block, is the temporary shear that VII containing engine oils experience in the bearing space at high journal speeds, which in turn produce high shear rates.

The temporary shear in addition to the reduced HTHS of a VII/VM containing engine oil should be a factor when choosing the right product for the application.

It seems to me that many people are buying an engine oil based on it's VI and cold flow attributes, while overlooking the reduced HTHS those lubricants may exhibit for a given KV100 specification.
 
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This is a rather technical discussion here used oil. But I agree with your hypothesis here. I agree that too many people are concerned with the W end of the spectrum and no where near enough with the 100°C end. I am wanting to continue to read up on higher HTHS oils that really be better for my car in the operating end of the spectrum. I've read where the motor in my car is apt at shearing oils down pretty good. So, I am all ears on this topic
smile.gif
 
Moi oci.

It will be interesting to see what SAE 16 brings to the table as far as density is concerned.

My guess is, 5W16 and 10W16 will have a HTHS comparable to 0W20, but with higher density.
That should equate to a flatter viscosity curve between 100C and 150C, improved temporary and permanent shear stability,
lower NOACK and a higher flash point.
 
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How would Red Line 0w-5 oil fit into your scheme?


Vis @ 100°C, cSt 4.6
Vis @ 40°C, cSt 21.8
Viscosity Index 134
CCS Viscosity, Poise, @ °C 20@-30°C
Pour Point, °C -54
Pour Point, °F -65
NOACK Evaporation Loss,1hr @ 482°F (250°C), % 12
 
I would call that an ISO 22 hydraulic oil.

At least Red Line had enough sense to refrain from putting SAE in front of a wild-cat grade.

My scheme?
 
Originally Posted By: OneEyeJack
How would Red Line 0w-5 oil fit into your scheme?


density and hths specs would help...

but as an example, it's probably bracketted by something like

http://exxonmobilchemical.ides.com/en-US/ds244592/SpectraSyn%20Plus™%204.aspx?I=30156&U=0
4cst PAO
KV40 - 17.2
KV100 - 3.9
density - 0.820
HTHS - 1.24Cp
Volatility
http://exxonmobilchemical.ides.com/en-US/ds244595/SpectraSyn%20Plus™%206.aspx?I=30156&U=0
6cst PAO
KV40 - 30.3
KV100 - 5.9
density - 0.827
HTHS - 1.86p
Volatility <6%
 
A guy with a pressure gauge selling VI.
An infomercial for $20/L Red Line, Motul, 0W20 TGMO and M1 0W40.
The correction for density at 150C.

Two or three posts above this one, industrial strength hydraulic oils at $4,000.00
a drum pressed into 16,000 rpm race engine service.

Other than the calculator what else applies to this topic?
 
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A similar discussion here:

Density and VII

My answer was this:

Originally Posted By: from Mola's 10/04 Post


No, the density is not determined by the VII or its percentage alone.

The density (not the API specific gravity) is determined primarily by the molecular weight (and viscosity) of the base oils used.

However, the total mixture determines the final density since some additives are thin and lower density, some are thick and have a higher density, so they average out.

The densities and viscosities of all the fluids in a formulation have to be considered.


I really don't see how anyone could effectively correlate density and HTHS because one would almost have to go with the third or fourth Density digit and HT/HS digits in order to Resolve any meaningful data, data which would mostly be in the noise.

In addition, I don't think the testing regimes or test rigs can give us the amount of resolution needed.

Correlation Coefficient
 
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Why do 0W40, 5W40 and 10W40 have a lower HTHS requirement
than 15W40 through SAE 40?

It almost looks like the 0W40-10W40s are just an improved XW30 in that regard.
 
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Originally Posted By: used_0il
Why do 0W40, 5W40 and 10W40 have a lower HTHS requirement
than 15W40 through SAE 40?

It almost looks like the 0W40-10W40s are just an improved XW30 in that regard.


I am not sure what you mean by "speced." The PDS gives the characteristics of a blended oil.

The wide viscosity grade oils have cuts of lower viscosity oils to help them span the grades.

Both Shannow and myself have posted how oils are blended:

Originally Posted By: excerpt from MolaKule
A base oil for a formulated PCMO is NOT one Single viscosity of base oil as I have explained many times here.

A formulator can take a binary blend (a blend of two base viscosities), or a ternary (a blend of three base viscosities), or an n-ary (a blend of "n" viscosities where n is any number) to make a base mix oil behave any way he desires.

------------------------------
For example a 5W30

PAO 4 14%

PAO 20 56%
------------------------------
A 5W40

PAO 4 20%

PAO 6 48%

PAO 65 2%

-----------------------------
A 10W30/30

PAO 6 25%

PAO 8 44%

PAO 150 1%


A 0W20

PAO 4 54.5%

PAO 6 15%

PAO 65 0.5%


AND,

http://www.bobistheoilguy.com/forums/ubb...de.#Post3808352
 
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