NOACK / GDI Valve Deposits / HTHS/Flash Point

[Grumpy Bear]

Stuff to think about. 

 

The API limit for NOACK for SN, SP+ and SP is 15%. 

The DEXOS 1 Gen 2 limit is 13%

The DEXOS 1 Gen 3 limit is 12.5%

 

NOACK is a thing because 'vaporized oil' transported via the PCV system is most of what accumulates on a GDI motors intake valves. The lower the NOACK the lower the valve deposits. Most 5W30 DEXOS licensed 5W30 oils will run around 10%. A few will crowd the upper limit. One, Pennzoil Ultra taps out at 7%. Mobil 1 at 8.5%. Good to know if you run a 4.3 LV1 or LV3. 

 

Problem is your 5.3/6.2 is calling for a 0W20 and as a whole PQIA says they average 12.5%! The lower the API classification the higher the average NOACK. The lower the number preceding the W drives it even higher. 

 

https://bobistheoilguy.com/forums/threads/mobil-1-ep-vs-pennzoil-platinum-0w-20-noack.299056/page-4

 

You will find a list at this link above. Not all of these oils are DEXOS 1 Gen 2 licensed but on a whole note that those that are run 10-13%. That leaves two groups outstanding.

 

First those so high as to not be licensed.

 

Second those with numbers better than those obtaining a license: 

 

AMSOIL 0W20 NOACK 8.5% / HTHS 2.67

Red Line 0W20 NOACK 9.0% / HTHS 2.9

MPT 30K 0W20 NOACK 8.8% / HTHS 3.2

 

Bonus material: In addition the two in bold above have a HTHS viscosity high enough to qualify as a *W30 class oil. That's the number important to ring wear. 

 

 

About 40% of a motors friction comes from the rings so HTHS has become a hot button for OEMS. Problem is low HTHS numbers also increase ring wear. Also camshaft and rod bearing wear. It is a straight up trade. Wear for fuel efficiency. EP additives will only help so much. If additives were the end all be all then we would run additives in water instead of oil. 

 

https://www.q8oils.com/automotive/low-hths-oils/

 

 

 

 

Edited June 30, 2021 by Grumpy Bear

[Grumpy Bear]

NOACK for the 5W30 4.3 Crowd

 

As mentioned in the first post: 

Mobil 1 EP 8.5% / Unpublished HTHS

Pennzoil Ultra 7% / Unpublished HTHS

 

Then we get serious:

 

AMSOIL SS 6.7% / HTHS 3.11

Red Line HP 6% / HTHS 3.7

MPT 30K 5.4% / HTHS 3.9

 

Both the bold above are high enough to pass W40/W50 and W60 specs for HTHS

 

If fuel economy is second on your list these 10W30's are in the running;

 

Red Line HP 6% / HTHS 3.5

MPT 30K 5.3 / 4.0 HTHS Now there is a track day or extreme tow motor oil. 

AMSOIL SS 4.1% / 3.11 

 

Two W20's I didn't mention in the first post for the V8's: 

 

Red Line 5W20 8% / HTHS 3.0 that is W30 HTHS territory in a W20 oil. 

MPT 30K 5W20 6.2% / HTHS 3.2 Both numbers in W30 territory. 

AMSOIL 5W20  5.8%

 

Edited June 25, 2021 by Grumpy Bear

[Grumpy Bear]

 

The intent of this chart is to show the benefits of fluids with a high VI. Normal use area doesn't mean that is your normal oil temperature range but rather summer use as opposed to the cold start range or winter used. 100 C is an interesting number and the fulcrum or pivot point VI is calculated around. Discussed in another post somewhere. Short version is VI is calculated as the viscosity difference between the 40 C and 100 C points, the smaller the number the higher the VI,  and that is where I get off this buss. 

 

A number not calculated but eluded to in this graph is the difference in viscosity between 100 C (104F) and 150 C (302 F), the HTHS point. This might have something to do with the difficulty in getting a fluid density at 150 C thus 'mixed units' of absolute vs apparent" viscosities. 

 

There is a thread on BITOG where a statement is made that oils like Red Line HP 0W20 are actually 30W due to their high HTHS numbers. This is a false statement. The SAE grading system does not classify the oils grade by it's HTHS value but rather it's 100 C value. The SAE 100 C number is a range, not a single point. A narrow range but still a range. The HTHS is a MINIMUM requirement for an oil that meets the SAE grade at 100 C. This means rationally that there are fluids that will meet the 20W specs at 100 C and still be to low to make it into a bottle of oil with the SAE certification. It is also possible the an oil meet the 20W spec at 100 C and far exceed the minimum HTHS requirement and that friends is a bonus in durability. It is also an opportunity. The reason I had no issue running 0W20 in my 4.3 that calls for a 5W30 or issues running 10W40 in my Harley that requires a 20W50. 

 

As my focus vacillates between economy and durability it may just be possible to have both with the right oil choice and capture both ends of this curve. Not often a guy can do that. Disclaimer:

 

NOT SOMETHING YOU SHOULD ATTEMPT IF YOU DON"T HAVE A FIRM GRASP ON THIS CONCEPT. 

 

Moving on. Note the words "Extreme Service" below the X axis? That is the absolute temperature of the oil where ever it may be in the motor. ALL motors and their oils operate in this range. The pan temperature for motors without oil coolers and the cooler outlet of those that do is the lowest temperature in the system. It's what your DIC reads if available. 

 

The ring area is the place the HTHS test is meant to replicate. 

 

Now tie this in with what you know about the Stribeck Curve and you might start seeing the value of PAO/POE oils, not just for extreme service but for daily drivers as well. 

 

There are plenty of oils that have a great VI number that 'just' meet their grades 100 C viscosity window. And if our motors lived between -40 C and 100 C I'd pay that more attention. Yes cold pumping ability is really important in colder climates but from cold start to normal pan temperature is 'transitional'. 20 minutes warming up and only about 5 of that in really cold weather under O C. But hours above 100 C. 

 

There is even a thread at BITOG that states some study where high HTHS and a high MOFT (minimum oil film thickness) destroys bearings and cause, get this, corrosion? Rubbish. It is the basis for hydrodynamic lubrication. 

 

This post is about 'flattening the curve"!

(Yes the pun is intended)

[Grumpy Bear]

Somebody on this forum has a signature that reads something like: 

 

Never argue with an idiot. They will drag you down and beat you with experience. 

 

It's not just funny, it's true!

 

Hope I got that right. Close enough. I just erased a long missive detailing the benefits of the few PAO/POE oils that are available and at its end I shook my head, sighed and erased it all. Who would I convince? Do I want to convince anyone? Will it have an effect on my equipment? Frankly, does anyone care? Trolls would show up and muddy the water....again. 

 

It is funny. Makes me laugh anyway. There are a dozens of so called Full Synthetics that are actually 100% mineral oil derivatives. The funny part is people drink that Kool-Aid everyday shelling out the price of a real synthetic for goats milk and happy as clams at high tide. Who am I to tell them tides going out. 

 

 

Knock yourself out. 

 

 

[Grumpy Bear]

 

3.7 cP is the HTHS viscosity of straight SAE 40 as assigned about 80 years ago and is the bases for the percent increases in fuel efficiency made my marketing types for lower SAE grades. If you work the math with the target HTHS value your answer reflects the percentage improvement in fuel economy COMPAIRED to an 80 year old standard. The improvement moving from a 40 W to a 5W20 is about 5%. 

 

In 1953 Kendal Oil introduced the first multi-grade engine oil. A 10W30. At that very point motor oils stopped being Newtonian Fluids. The culprit was and is the high molecular weight polymeric thickening fluids used to increase VI. They make the lubricant act funny when stressed and not in a good way. 

 

WIKI gives us this on Newtonian Fluids: A Newtonian fluid is a fluid in which the viscous stresses arising from its flow, at every point, are linearly correlated to the local strain rate—the rate of change of its deformation over time. ... Newtonian fluids are the simplest mathematical models of fluids that account for viscosity.

 

Hum. So under stress it draws a straight line in viscosity reduction. So what does an oil with VI improvers do? 

 

 

They are Pseudoplastic. They shear thin.

 

So how is that useful information?

 

A mineral based oil that requires a VI polymer will have a lower HTHS value than a PAO/POE oil that does not use a polymeric thickener. You get the lower viscosity of the lighter SAE grade and keep the wear resistance a higher HTHS. 

 

Let that sit in your brain a few minutes and tell me base oil does not matter. 

 

 

How about NOACK vs Base oil type

 

Tell me base oil does not matter and it's all in the additives. 

 

Know what happens to HTHS when the oil is diluted with fuel? You won't get that number back on  your UOA but it's easy enough to estimate. It will fall about the same percentage as the fall in 100 C viscosity. Falls far enough and? Catastrophic parts failure. The PAO/POE gives you about a grade more cushion to failure by remaining Newtonian. Thank you no VI improvers. 

 

Do GDI motors suffer fuel dilution? 

 

Edited June 30, 2021 by Grumpy Bear

[TxVet33]

12 minutes ago, Grumpy Bear said:

Is that some of that “new” common core math???

[Grumpy Bear]

29 minutes ago, TxVet33 said:

Is that some of that “new” common core math???

 

Go back and read again. I was testing if it would take the post. I worked a couple of hours on it and it would not accept my post so I rebooted and BINGO. It loaded this time. 

[Grumpy Bear]

Flash Point

 

(Lube Media Source)

 

I chose this chart to show a thing called the "Law of Partial Pressures" Concentrate on the flash point line and note that a 50/50 blend of Naphthenic/Paraffinic oils produces a flash point about mid way between those of the parent oils. 

 

But it also hints to a concept where one can uncover, maybe, some truth about the oil in that bottle you just bought. 

 

We know that VI can be enhanced with VI improvers making an oil seem to be of a higher base stock than it is. Spoiler alert. It will not raise the flash point. Meaning that Hi VI products with lower flash points are not what they seem. 

 

(Machinery Lubrication Source)

 

ISO VG is just another method for viscosity classification and corelates to the SAE system. So keep you eye on the ball. 

 

No matter what the base oil as it's viscosity increases so does its flash point so you can only compare the information I opened with to other oils of the same SAE classification. That is, a 5W30 to another 5W30. 

 

**************************

 

One I can not find a visual aid for in the same viscosity is base oil type vs flash point but it goes as one would expect. The higher the Base Group the higher the Flash Point and not by a little either. Flash of a Group V NPG Polyol Ester is almost DOUBLE that of a Conventional Group II.

 

**************************** 

 

 

 

And flash point can be manipulated with Nano Lubricants. But that raises pour point along with the flash point.

 

https://www.researchgate.net/figure/The-flash-point-values-of-parent-oil-and-nano-lubricant-From-Fig-11-it-has-been_fig7_335205883

 

The link is the source of the graph and also a good read if you enjoy that sort of thing. 

 

CuO is Cupric Oxide an EP additive. 

MWCNT's are carbon nano tubes. (some use in diesel oils) 

 

Point being the properties of a lubricant can and are manipulated by the formulator BUT the results are still subject to the chemistry, the physics the Laws of God. Every manipulation of a Mineral Oil has it's intended positive effect and some opposite downside.

 

Here's a spoiler alert. Marketing will cash in on the positive and slide pass on the negatives. 

 

Satan was a marketing executive.  

 

He told Eve that eating the fruit would "Make her like God knowing good and bad". 

The spoiler was it cost her her life.

 

Know what the only downside of Group IV/V blend is as it pertains to automotive crankcase lubrication?

Cost...that's it....Cost 

 

 

Edited June 30, 2021 by Grumpy Bear

[Grumpy Bear]

HTHS and Shear Stability INDEX

 

https://www.lubesngreases.com/magazine/24_9/shearly-staying-in-grade/

https://www.oronite.com/products-technology/viscosity-modifiers/default.aspx

Kurt Orbahn Diesel Injector Test

 

A viscosity modifier polymer’s Shear Stability Index (SSI) is defined as its resistance to mechanical degradation (polymer coil breakage) under shearing stress. Example: An oil is formulated with base oil of viscosity 5 centistokes (cSt) and a viscosity modifier is used to increase its viscosity to 15 cSt. The viscosity modifier’s viscosity contribution is therefore 10 cSt. During the shear test, the oil’s viscosity falls to 12 cSt. It has permanently lost 3 cSt of viscosity. The viscosity modifier polymer’s shear stability index (SSI) is therefore 3 cSt (loss) divided by 10 cSt (viscosity modifier contribution), or 30% SSI.

 

********************************************************************************

 

So much knowledge, so little understanding.

 

Viscosity is the most important aspect of your motor oil. It is what creates a the film thickness that protects your motors moving parts and there are allot of working parts to KEEPING the viscosity the fluid has to keep it grade. Instead of rambling over each point I provide two links to get you going plus a 'key word' for your searches but I am going to list some highlights and some lowlights.

 

1) Base oils are Newtonian fluids and are shear stable. ALL of them Mineral, PAO, POEs. 

2.) VM's (viscosity modifiers) added to the base oils CREATE NON-Newtonian fluids

3.) VM's added to base oils to make them "MULTIGRADE" are NOT shear stable, some more than others.

4.) Under shear stress (a running motor) these VM added to the base thin viscosity.

5.) Some of the loss is temporary and some permanent. Shear stability is a measure of the degree of permanent loss.

 

Not much of this has been made for a couple of reasons. The first is cost. The most shear stable VM's are the most costly and so the supplier would rather not tell you he is 'meeting spec' but 'not for long'. The second is that until DEXOS1Gen2 where cleanliness became a bigger concern that this viscosity loss was offset by shear thickening caused by a buildup of solids in the oil. So some more highlights....

 

1.) VM's breaking down CREATE solids just like acids and fuel byproducts do. They contribute to LACK of motor cleanliness. The less stable the VM the more it contributes to dirt. 

2.) The wider the difference between the base oils natural 100 C viscosity and the VM 'thickened' viscosity the higher the percentage of VM required 'by kind' to meet the spec

3.) The VM's dose rate is also a function of MW (molecular weight) and molecule structure. Again the more shear stable it is the lower the dosing rate but the cost is inverse. 

4.) The larger the difference between the first and second number of the SAE grade the greater the dose rate and the higher the MW of the VM is needed to meet it's spec. That is 10W30 is more stable than 0W30. 

 

Viscosity loss can NOT be offset by AW or EP additives. They are no substitute for film thickness. 

 

Listen very carefully to the next part....

 

A well formulated PAO/POE contains ZERO VM content. It is Newtonian and shear stable. 

 

https://www.redlineoil.com/Content/files/RLO_PRODUCT_CATALOG_2019.pdf

 

https://mptindustries.com/product-category/thirty-k-full-synthetic-high-performance-motor-oils/

 

[Grumpy Bear]

HTHS and Shear Stability INDEX 2

 

https://bobistheoilguy.com/forums/threads/kirkland-5w-30-oil-specs-from-warren.321289/

 

Give page two of this document a look. About half way down a test ASTM D6616 The high shear viscosity at 100C NOT 150 C and NOT the ASTM D445 100C viscosity you normally look at. This is the viscosity in the high shear areas of your motor and it's a smaller number than you would believe it to be. With repeated trips to the shear zone this temporary number becomes permanent. Oil falls out of grade. 

 

 

Best graph I could find on line for shear rate vs viscosity loss. The locations giving differing rates for the same rpm. You should be able to visualize that shear increases with rpm apart for location as well. Pick out the Red Line 5W30-10W30 line and note that viscosity does not change? This is not a function of the base oil or the name on the bottle but a function of the absence of VM's used to increase VI. PAO's and POE's have a naturally high VI and if the right ones are chosen during blending little to ZERO VM's are required and ZERO PPS (pour point suppressors) is required. 

 

While we sleep SN+ is phasing out and SP is taking root. Soon enough SN/SN+ will go the way of SC oils. Ditto in the world of diesel oils where Cj-4 is being replaced with CK-4-FA-4. These new classifications are LOWEING HTHS viscosity to as low as 2.6 cP in the 0W20 oils. A tick below their peak effectiveness value for BOTH wear and fuel efficiency and relying heavy on AW additives and lubricity additives such as Boron and Moly to reach ever stricter EPA goals. But when you are at the same time removing phosphorus and zinc (ZDDP) increased wear in the result and you are rapidly running out of tools to fight this loosing battle. 

 

You have limited methods left. Use of PAO/POE's that do not contain VM's or PPS and/or increase the service grade back to a safe level. That is move from W16-W20 to W30 or Move from 'Full Synthetic" to PAO/POE oils. 

 

They can preach "improved" lower shear sensitive STAR VM's till pigs fly but a 2.6 cp HTHS is still the same pig. 

 

Lower HTHS targets, Lower Phos and Zinc targets. Lower Calcium thus TBN targets. Cheaper and cheaper bases as additive cost and development increases. And the head scratcher in all this the insistence that in spite of all this we are going to increase power density, heat and tell you to change your oil less frequently. 

 

Can you say forced electrification? Or perhaps the need to spend 100K every three years when motors are failing faster than Model T engines.