LSJr - Viscosity Breakdown: The Silent Engine Killer Revealed!

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No surprises here. We all knew here that Mobil1 0W40 is shear stable for an off-the-shelf, readily available oil.
Also, no surprise that Castrol Euro 5W40 sheared more than M1 0W40. IMO, and I always claimed this, Castrol Euro 5W40 was never on par with M1 0W40. It would be interesting, though, to see how Castrol Euro 0W40 and 0W30 would perform.
Other tests were no surprise, though what caught my attention was difference in star polymers between two suppliers.
 
Star polymer VII's are generally Star-shaped poly(alkylmethacrylate)s (PAMAs) of dodecylmethacrylates with polar methacrylates. Here is more info on them.

Core-Crosslinked Star Copolymers as Viscosity Index Improvers:
for Lubricants

https://pubs.acs.org/doi/pdf/10.1021/acsapm.2c01039

Here is Shell's patent on Styrene VII's

https://patentimages.storage.googleapis.com/5e/74/b2/918ab768bea0ee/US5458791.pdf

BTW, sometimes various types of VII's are mixed in order cover all bases.

A good explanation of these polymers for the chem nerds is found in Chapter 11 of Lubricant Additives Chemistry and Applications, edited by Leslie Rudnick.
 
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What do you mean by cleanlines?

Are you referring to the basic chemistry? If so they are usually clear chemistries and very pure as shown in the beakers in the video.

Or are you referring to for example after they are sheared or oxidized or burned??
Sorry should have been clearer. When they are sheared/burned.
 
Another great video from LSJ. The Mobil 1 0w40 result is much better than I would have expected.

Are there differences in cleanliness among the polymers?
That KRL probably simulates more engine time than you expect. The loss of viscosity from the KRL on the Mobil 1 0W40 in the video, was about the same as the loss of viscosity in a 10,000 mile run on my Mercedes S600.

So, quite a useful test. Now, every engine is different - but the V-12 is a timing chain engine with turbos - so, it’s not going to be as easy on the oil as some.

https://bobistheoilguy.com/forums/threads/m1-0w40-8-946-mi-mercedes-v-12-m275.195665/

https://bobistheoilguy.com/forums/threads/mobil-1-0w40-10-145-miles-mercedes-m275-v-12.270464/
 
Sorry should have been clearer. When they are sheared/burned.
Also, are the sheared/burned polymers “sticky”, and if so, is this where ANs and Esters are used to solubilize them and keep them from accumulating?

If one took the base chemistry of a no VII oil and one with shear-prone VII, would they generate the same amount of deposits/particulates under the same conditions, or do the sheared VIIs have a tendency to fall out of suspension & accumulate on low-flow surfaces?
 
KRL is "kegel-rollen-lager" which is German for "Tapered roller bearing". A 20 ml sample is poured in the bearing, the case is sealed, and a 4-ball machine applies the load and rpm to see how much the oil shears in the bearing. It's not about what the oil does to the bearing but what the bearing does to the oil. It's a more common test for gear oils but correlates quite well with engine oils also.

The other samples are blends HPL made for the test with no add pack or other variables, just base oil and VII. They tested 4 different VIIs with both group III and IV base oils.
Thank you!
 
No surprises here. We all knew here that Mobil1 0W40 is shear stable for an off-the-shelf, readily available oil.
Also, no surprise that Castrol Euro 5W40 sheared more than M1 0W40. IMO, and I always claimed this, Castrol Euro 5W40 was never on par with M1 0W40. It would be interesting, though, to see how Castrol Euro 0W40 and 0W30 would perform.
Other tests were no surprise, though what caught my attention was difference in star polymers between two suppliers.
Percentage-wise yes, but it still has a higher HTHS, no? Interesting that M1 is barely over 3.5 to start now.
 
That KRL probably simulates more engine time than you expect. The loss of viscosity from the KRL on the Mobil 1 0W40 in the video, was about the same as the loss of viscosity in a 10,000 mile run on my Mercedes S600.

So, quite a useful test. Now, every engine is different - but the V-12 is a timing chain engine with turbos - so, it’s not going to be as easy on the oil as some.

https://bobistheoilguy.com/forums/threads/m1-0w40-8-946-mi-mercedes-v-12-m275.195665/

https://bobistheoilguy.com/forums/threads/mobil-1-0w40-10-145-miles-mercedes-m275-v-12.270464/
Yes, HPL seems to have a good plan going. The 3.5 EcoBoost is not known to be gentle on oil either, and combined with some folks’ fuel dilution it can get ugly in a short OCI.

The No VII Euro in my truck (which is being drained in about 20 minutes @16k+ miles) thickened up from 11.19 to 12.7 cSt in 14,400 miles. Fuel was <1% by GC, so I feel this really shows some of the shortcomings of shelf oils compared to HPL and some extent Amsoil & Redline on certain oils.

I’m not going to run another UOA at this point, but I think the results show that the 3-5k OCI histrionics are far overblown and solely dependent on proper oil choice. SuperCar 0w30 is going in, I’ll check back in another 15k or so with that UOA to see how No VII Euro & SuperCar compare back to back!

https://bobistheoilguy.com/forums/t...4-4k-hpl-no-vii-euro-5w30.382751/post-6886836
 
Percentage-wise yes, but it still has a higher HTHS, no? Interesting that M1 is barely over 3.5 to start now.
M1 stated 3.6. But that is typical value.
Castrol never stated HTHS for their 5W40, but some correspondence with Castrol done by members of some other forums, claim 3.64.
That is not that good for such KV100. Motul for example claims HTHS 3.8 from 13.5cst.
 
Missing from the KRL test is the effect of evaporation losses over an oil drain interval.
Before noack was a thing, an engine oil could be kept in grade by the intended evaporation of low boilers.
Pre-noack, the ability of an engine oil to stay in grade was not necessary an indication of quality, but could be achieved by crafty blending.
 
Sorry should have been clearer. When they are sheared/burned.
The OCP's are probably the ones that leave the most depositis when burned.

The PIB's usually burn clean, which is why they are often used in two-cycle lubricants.

The Star poly(alkylmethacrylate)s (PAMAs) burn fairly clean as well.

Shearing simply means molecular separation of the molecular 'arm' structure. See the references I mentioned above.
 
Missing Shell/Pennzoil GTL oil in this test.
Would be interesting too see they would do better then M1 0W40 FS.

Shell was/is not selling all variants of GTL base oils on the open market, maybe someone can confirm.
 
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So I'm wondering about using the No VII 5-30 in my MB3.5 engines which call for 229.5 spec. Any thoughts out there? I have HPL Euro 5-40 in one of them. Mobil 1 0-40 in the other.
 
So I'm wondering about using the No VII 5-30 in my MB3.5 engines which call for 229.5 spec. Any thoughts out there? I have HPL Euro 5-40 in one of them. Mobil 1 0-40 in the other.
HPL makes a Euro No-VII 5W-30 as well as PCMO No-VII 5W-30. I would stick with Euro spec for the MB engine.
 
Missing Shell/Pennzoil GTL oil in this test.
Would be interesting too see they would do better then M1 0W40 FS.

Shell was/is not selling all variants of GTL base oils on the open market, maybe someone can confirm.
As in wondering what type in quantity of VM is used in those products? The base stock isn’t going to shear regardless of the manufacturing process.
 
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