Shearing, dilution and low cSt questions

[ZeeOSix]

Here's one with

Pentosin Euro 5w40, 10k miles on the oil, on a MB 2005 S500 with 215k miles

Pentosin Euro 5w40, 10k miles on the oil, on a MB 2005 S500 with 215k miles

bobistheoilguy.com

 

[ZeeOSix]

Here's some 5W-30 Motorcraft synthetic with 9,146 miles and 0.5% fuel dilution that sheared out of viscosity spec. Virgin KV100 is 10.5 cSt. So most of that 22.7% viscosity reduction must have been mechanical shearing.

https://www.motorcraft.com/content/dam/ford-motorcraft/en_us/motorcraft_global/products/pdf/SAE_5W_30_Full_Synthetic_Motor_Oil/Product%20Data%20Sheet%205W30%20Full%20Synthetic.pdf

UOA: 2019 Ford Ranger 2.3T Ecoboost

This is with the Ford Performance engine tune and the K&N air filter that goes with it. TBN is still good at 9k and OLM at 8%, 10k would be fine which is where the OLM would have been about at 0%. This is "normal" commuting and a few road trips. Motorcraft full synthetic 5w30 in and out, MC...

bobistheoilguy.com

 

[OVERKILL]

Just found this old thread on the subject, which unfortunately links to a document that doesn't exist:

Oil shear?

Is there any evidence that lower cost synthetic oils (ST, Form Shell, Parts Master, Etc,) shear down faster then the so called top tier oils (M1, PP, Amsoil, etc) of the same oil weight?

bobistheoilguy.com

1. New international specifications ACEA and API require that the shear stability of engine oils is tested by 90 cycles of oil passing through the nozzle instead of current 30 cycles; these requirements are accepted by a number of vehicle manufacturers.

2. Shear stability determination according to new ASTM D 7109 method has been defined with 90 cycles of testing.

3. Different concentrations of viscosity index improvers are needed for production of multigrade engine oil of the same viscosity; the highest additive concentration is needed for the viscosity index improvers based on OCP.

4. Viscosity index improvers based on OCP have the best shear stability after 90 cycles of testing.

5. Engine oil with the viscosity index improver based on styrene-isoprene (C) has a significant viscosity loss after extended testing from 30 cycles to 90 cycles and it does not meet requirements of the new international and OEM specifications.

So, that's interesting.

It links to a 2008 thread by JAG:

Viscosity Index Improver Testing

http://hrcak.srce.hr/file/37720 "ENGINE OIL VISCOSITY INDEX IMPROVER BEHAVIOUR AT EXTENDED SHEAR STABILITY TEST" From February 2008, so it's very recent. The gist of this is that two common types of VIIs (Polymethacrylates (PAMA) and Hydrogenated styrene-diene copolymers) used in motor oils...

bobistheoilguy.com

which states:
"ENGINE OIL VISCOSITY INDEX IMPROVER BEHAVIOUR AT EXTENDED SHEAR STABILITY TEST" From February 2008, so it's very recent. The gist of this is that two common types of VIIs (Polymethacrylates (PAMA) and Hydrogenated styrene-diene copolymers) used in motor oils failed the 90 cycle shear stability requirement and only one type (Olefin copolymers (OCP)) passed.

And:
The new ASTM D 7109 method for shear stability testing has been established which differs in more testing cycles and sample quantity than the previous ASTM D6278 [6,7]. By introduction of the new ACEA (Association des Constructeurs Européens d'Automobiles) and API (American Petroleum Institute) specifications, the changes in requirements for determining shear stability of engine oils aroused. The new ACEA E6-04 and E7-04 specifications than API CI-4 Plus and API CJ-4 set more stringent requirements for the shear stability with the use of the same method, but with 90 cycles instead of the previous 30 cycles of testing [5]. Apart from ACEA and API specifications, determining shear stability of oils with 90 cycles tests, is also required by some engine and vehicle manufacturers, for example, Mercedes-Benz – all the specifications, Volvo for VDS-3 and VDS-4 and other manufacturers in relation to ACEA and API specifications. All of them require that kinematic viscosity at 100 °C after shearing remains within SAE J300 classification grades (Table 1).

So it looks like the API only uses it on HDEO's, while it's more prevalent in ACEA and the OEM protocols.

 

[OVERKILL]

Here's one with

Pentosin Euro 5w40, 10k miles on the oil, on a MB 2005 S500 with 215k miles

Pentosin Euro 5w40, 10k miles on the oil, on a MB 2005 S500 with 215k miles

bobistheoilguy.com

Can't use the Blackstone fuel figures unfortunately, they are WAY off, that's what I meant when I was remarking on GC fuel dilution. The majority of the UOA's we see are Blackstone and they don't use GC, they just infer fuel from a generic flashpoint figure, which can be so far off it is useless.

 

[OVERKILL]

Here's some 5W-30 Motorcraft synthetic with 9,146 miles and 0.5% fuel dilution that sheared out of viscosity spec. Virgin KV100 is 10.5 cSt. So most of that 22.7% viscosity reduction must have been mechanical shearing.

https://www.motorcraft.com/content/dam/ford-motorcraft/en_us/motorcraft_global/products/pdf/SAE_5W_30_Full_Synthetic_Motor_Oil/Product%20Data%20Sheet%205W30%20Full%20Synthetic.pdf

UOA: 2019 Ford Ranger 2.3T Ecoboost

This is with the Ford Performance engine tune and the K&N air filter that goes with it. TBN is still good at 9k and OLM at 8%, 10k would be fine which is where the OLM would have been about at 0%. This is "normal" commuting and a few road trips. Motorcraft full synthetic 5w30 in and out, MC...

bobistheoilguy.com

Another Blackstone UOA unfortunately, can't use the fuel percentage.

Look for labs that use GC, those are the ones that give us proper fuel measurement. There were a few UOA's done that compared Blackstone to a lab that does GC and the difference was staggering as to the variance in the fuel % figure.

 

[ZeeOSix]

Can't use the Blackstone fuel figures unfortunately, they are WAY off, that's what I meant when I was remarking on GC fuel dilution. The majority of the UOA's we see are Blackstone and they don't use GC, they just infer fuel from a generic flashpoint figure, which can be so far off it is useless.

I was wondering what method Blackstone used. Good to know.

 

[OVERKILL]

I was wondering what method Blackstone used. Good to know.

Here's one that's GC, unfortunately, it's on a premium 0w-8, so probably no VII's, lol:

2022 Honda Insight HPL PP PCMO 0W8 4497 Miles

 

[OVERKILL]

Here we go! Apparently Oil Analyzers uses GC:

Shell Rotella Gas Truck 0W20, 5,000 miles, 2019 RX 350

A little over a 5k mile run with Shell Rotella Gas Truck 0W-20 and an OEM Toyota filter - there is 25k on the vehicle. Fuel dilution is a little high - my wife short trips a bit as this is mostly an "in town" vehicle with some highway. The high Ti is most likely due to the previous oil used -...

bobistheoilguy.com

So, that one shows 1.6% fuel.

 

[OVERKILL]

Give me a minute to run the RTG figures based on that fuel %.

 

[OVERKILL]

K, virgin is apparently 8.4cSt nominal (assuming he was using the SP version):

https://www.shell-livedocs.com/data/published/en/524488ae-e09a-43fe-bd4f-784572fd66f3.pdf

So, adding 1.6% fuel at 0.55cSt gives us 8.0cSt according to the Widman calc, so the other 0.6cSt is shear I would assume, so, fudging for variability, in this case we could ascribe half the visc loss to shear, the other half to fuel.

Now, interestingly, his previous report was with Blackstone, that determined he had <0.5% fuel....

 

[ZeeOSix]

No, it's not as bad, but MPFI engines still can dilute, my SRT HEMI's all did and so did the S62 in my M5, considerably (5% fuel in one case).

I know it's subjective, but do you recall if you could really sense the smell of "gassy" oil at 5% dilution?

 

[OVERKILL]

I know it's subjective, but do you recall if you could really sense the smell of "gassy" oil at 5% dilution?

Not on the dipstick, but when I changed it? Yes, you could smell the fuel a bit.

 

[DirectRejection]

Toyota is the only marque I know of off the top of my head that has a hybrid GDI/MPFI setup. I outlined the caveats of GDI quite clearly in the post you responded to.

It's not just higher compression, it's the ability to manipulate the timing of the injection of the fuel to facilitate it, which you can't do with MPFI because it depends on the timing of the intake valve. That's how you can get away with higher compression ratios, boost, and 87 octane with GDI.

Ford was/is using reversion to "wash" the intake valves with the air/fuel charge on the EcoBoost as their way to mitigate IVD's, this was done with manipulation of the camshaft timing. Toyota has claimed their hybrid setup is to improve low speed performance/drivability, which is where their engines use MPFI, but of course keeping the intake valves clean is an obvious benefit of that system.

Personally, despite the performance benefits, I'm wary of GDI. Honda has had some considerable issues with fuel dilution, then there is LSPI, costly injection pumps, injectors...etc. While it shouldn't be a technology in its infancy at this point, given the considerable time that has elapsed since its introduction, in many ways it still feels like it is.

I was very impressed with Toyota's setup, based upon 160k miles on my previous 2019 Lexus UX 250h.

My 2022 Honda Insight is MPFI, and this was a factor in my recent purchase.

 

[FZ1]

I read a lot and post infrequently but this is a topic that I can't quite wrap my head around and perhaps the answer is obvious and I just don't see it.

I'm going to use PP 5/30 as an example but any other oil in the same grade with a 9 range cSt would be similar, I think.

We know that that shearing and dilution decrease the viscosity and Pennzoil, like the the others, routinely say their oil is resistant to shearing and stays in grade but they don't know what vehicle the oil is going on. If you have a diluter, such as certain Honda's, the oil is going to thin out without question.

If I run a recommended interval of say 5 -10k, the oil will shear or be diluted to a degree and my concern is that a thin 30 will end up as a thick 20 somewhere along the way. Running a 30 that has a cSt of 10 to 11 doesn't concern me.

I suppose I could understand using the PP 5/30 if I was driving a lot on a highway but driving around town a lot, I have my doubt the PP would be ideal and end up a 20. Wouldn't I better off using a higher cSt 30? Conversely, a car calling for a x/20 that dilutes or shears would seem to benefit from running the PP.

If you're worried about Vis loss just change the oil more often.

 

[FZ1]

Toyota is the only marque I know of off the top of my head that has a hybrid GDI/MPFI setup. I outlined the caveats of GDI quite clearly in the post you responded to.

It's not just higher compression, it's the ability to manipulate the timing of the injection of the fuel to facilitate it, which you can't do with MPFI because it depends on the timing of the intake valve. That's how you can get away with higher compression ratios, boost, and 87 octane with GDI.

Ford was/is using reversion to "wash" the intake valves with the air/fuel charge on the EcoBoost as their way to mitigate IVD's, this was done with manipulation of the camshaft timing. Toyota has claimed their hybrid setup is to improve low speed performance/drivability, which is where their engines use MPFI, but of course keeping the intake valves clean is an obvious benefit of that system.

Personally, despite the performance benefits, I'm wary of GDI. Honda has had some considerable issues with fuel dilution, then there is LSPI, costly injection pumps, injectors...etc. While it shouldn't be a technology in its infancy at this point, given the considerable time that has elapsed since its introduction, in many ways it still feels like it is.

Agree. I bought my 17 Camry because it had MPFI and a 6 speed auto vs. Accord with DFI and CVT.

 

[avss1]

ENGINE OIL VISCOSITY INDEX IMPROVER BEHAVIOUR AT EXTENDED SHEAR STABILITY TEST" From February 2008, so it's very recent. The gist of this is that two common types of VIIs (Polymethacrylates (PAMA) and Hydrogenated styrene-diene copolymers) used in motor oils failed the 90 cycle shear stability requirement and only one type (Olefin copolymers (OCP)) passed.

The viscosity loss depends on both VII type and its SSI (Shear Stability Index). OCPs have a typical SSI range from 24 to 50. Star styrene-diene VIIs have a typical SSI from 4 to 28. There is no OCP that can be better than a Star VII with SSI 4 even after 90 (or 120 or …) cycles.

 

[OVERKILL]

The viscosity loss depends on both VII type and its SSI (Shear Stability Index). OCPs have a typical SSI range from 24 to 50. Star styrene-diene VIIs have a typical SSI from 4 to 28. There is no OCP that can be better than a Star VII with SSI 4 even after 90 (or 120 or …) cycles.

Please note that the cited conclusion is from member JAG, who I don't believe participates here anymore unfortunately.

Of note however, the paper he quotes (remember, this is 2008) is addressing two types of Styrene-diene products:

2.3 Hydrogenated styrene-diene copolymers
Depending on the type of present diene, there are styrene-butadiene (SBC) and styrene-isoprene (SIP) polymers. They have the optimized molecular weight which resists shear stresses when used in engine oils [1,2]. Styrene-isoprene copolymers have good high temperature and low temperature properties (pumpability). The molecular weight of styrene-isoprene polymers is between 50000 and 100000 g/mol [1,4]. They are most widely used in engine oils. They can also be used in other fields of application with more stringent requirements for shear stability, for example as tractor transmissions fluids and airplane piston engine oils.

From the paper:

The testing of shear stability of multigrade engine oils was performed by ASTM D 7109 method on samples with SAE 15W-40 viscosity grade. The same additive package (DI) has been used, with the same initial values for kinematic viscosity at 100 °C (KV 100 = 14,5 ± 0,1 mm2 /s) and dynamic viscosity at -20 °C (CCS -20 = 6 650 ± 50 mPa⋅s), but with addition of three types of commercial viscosity index improvers. The viscosity index improvers based on polymethacrylates (A), olefin copolymers of different manufacturers (B1, B2, B3 and B4) and styrene-isoprene copolymers (C) were compared. The aim of testing was to determine if the mentioned viscosity index improvers with extended test of shear stability (90 cycles) meet requirements of the new engine oil specifications. The research is performed in two phases. For determining of viscosity loss the sample has been taken after 30 and 90 cycles. Table 2 show test results of the engine oil shear stability depending on type and concentration of polymeric viscosity index improvers.

The data from the table 2 show that for the formulating of engine oils with conditions given in advance, the kinematic viscosity of base oils at 100 °C of certain samples did not differ significantly (0 – 0,37 mm2 /s) which is shown on Figure 2. Simultaneously, the concentration of viscosity index improvers was quite different (Figure 3) and significantly bigger for improvers based on OCP in relation to those improvers based on polymethacrylates (A) and styrene-isoprene (C).

The table:

I've also attached the document, as I was able to find it via the web archive, in case you want to read it.

 

[avss1]

I've also attached the document, as I was able to find it via the web archive, in case you want to read it.

Thanks, I am familiar with this article. it's a matter of choice)))
Results are typical for OCPs, but not for ”market general” sterene VIIs.
Here results from oil-club.ru for Mobil 1 FS 5W-40. (sorry for Russian). Viscosity loss after 90 cycles 0,9%.

 

[OVERKILL]

Thanks, I am familiar with this article. it's a matter of choice)))
Results are typical for OCPs, but not for ”market general” sterene VIIs.
Here results from oil-club.ru for Mobil 1 FS 5W-40. (sorry for Russian). Viscosity loss after 90 cycles 0,9%.
View attachment 76016

I think we have to take into consideration the age of the paper. I expect that poorer performing examples may have been more popular before the standards revision the article describes. Clearly, the ones analyzed as part of this paper were not top shelf, given the results.

Excellent performance from That 5w-40 BTW.

 

[ChrisD46]

There is new growing concern over GTL base stocks in PP , PUP and the new QSUD replacement (70%+ GTL base) to be suspect in certain engines (i.e. louder , sheering , questionable protection , no long drain options , etc.) PP and PUP may be the tops in SOPUS line up for cleaning but I have moved on to Valvoline Advanced / EP 5W30 and M1 5W30 EP .