Low Viscosity doesn't have to mean low quality

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Originally Posted by Garak
Originally Posted by ka9mnx
I've often wondered if the increased bearing width to accommodate thinner oils didn't negatively offset the desired results of the thinner oils. Boundary and mixed, with the right additives, will always win the hydrodynamic race but running in those modes is running a fine line between success and failure in my opinion.

Someone here, likely Shannow, though I'm not trying to put him on the spot, mentioned that point before, and might be able to elaborate.


As I've stated previously, some of the Honda stuff is looking at the pistons as still somewhere to go.

My belief is that they are chasing that, even 'though they have to make the bearings that little bit less efficient.
 
Originally Posted by Gokhan

You totally missed the whole point. Wordings in the USA and Germany owner's manuals are identical. Toyota doesn't distinguish between US and Germany or interstate and autobahn.

0W-20 works in engines where it's recommended, regardless of the country it's used in and regardless of how fast the vehicle is driven. In fact, it works better -- you get better fuel economy, more horsepower, smoother takeoffs, and smoother-running engine overall. No Toyota engine has ever failed on a German autobahn because it used 0W-20. Did you somehow miss the line in the German owner's manual that it's the factory fill in German Toyotas? Factory fill in German Toyotas intended for German autobahns!


Not arguing, it is silimar if nor identical. The thing is, it doesn't matter because Europeans are bound to FE regulations just as NA units are bound to EPA, they're just a bit behind but they're going to get there. The rollout of RC 20's has been a bit of a cakewalk in North America, the perfect market to rollout first in, second maybe to Japan. They drive even gentler than us, and our operating duty cycle is light. The fact that the "alternative" grade severe service language is even included in the manual tells you everything, even though they are not legally allowed to recommend a 5W30- they must specify the grade oil used to qualify in the regulatory cycle test, and that would be the 0W20. They could just say use 0W20 and that's it, but they didnt stop there and offered conditional advice
 
I have seen owner's manual of the same Toyota engine specifying 0WX20 in US and 5Wx30 and 10Wx30 outside US. So there is some fascination with 0Wx20 in US. It won't blow up the engine but maybe even 1 drop of fuel saving per week per car over time and millions of car will add up ... Maybe cafe people are after this concept and oil companies can milk the consumer with more expensive oil so it's a win win for both of them and maybe the environment . However big corporations pollute the environment and cafe people should go after them as well. I don't want to be forced to drive an electric car unless it's speaker make a nice V8 sound
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Originally Posted by StevieC


This is complete Nonsense and you know it.


Study of synthetic 5W30s...no 4 on their page of technical reports
https://www.amsoil.com/lit/g3115.pdf

Oils, as can be found currently on their site...note "applications" rather than "specifications met"
https://www.amsoil.com/lit/international/databulletins/I3405_P400.pdf
https://www.amsoil.com/lit/databulletins/g3395.pdf
https://www.amsoil.com/lit/databulletins/g3418.pdf
https://www.amsoil.com/lit/databulletins/g2133.pdf
https://www.amsoil.com/lit/databulletins/G3114.pdf
https://www.amsoil.com/lit/databulletins/g27.pdf

For some relatively "fresh" data sheets, as I said...it's in their blood...
 
Thanks, StevieC for posting this. I just read the short article in the original post. The title is very interesting. Can you actually make up for lower oil viscosity by higher base-oil quality so that you actually have more protection against wear with a thinner oil than you would with a thicker oil of lower base-oil quality? This is the million-dollar question. Some here will jump and say, no way, viscosity is what lubricates! Unfortunately, it's not that easy. Why? Because viscosity is not a single number. It's something that not only depends on the temperature but also load pressure. In fact, it gets even more complicated because modern oils are multigrade and use viscosity-index improvers (VIIs) to increase the viscosity. But how do VIIs react when pushed to their limits?

Consideration A:

One interesting comment in the article is about the oil-film strength and how 0W-16 oils require the best base oils. Indeed, Mobil 1 0W-16 is PAO-based and Mobil Super 0W-16 is GTL-based. As far as I remember, TGMO 0W-16 is the same as Mobil Super 0W-16. So, no more Group III with 0W-16, at least so far.

Oil-film strength means the pressure - viscosity coefficient (PVC). It means how much the oil film can be squeezed under the load pressure before metal-to-metal contact occurs, in other words the failure of the elastohydrodynamic lubrication (EHL) and start of the boundary lubrication.

The tricky part with the PVC is that it's strongly temperature-dependent, decreasing sharply with the temperature. Group I mineral oils have much higher PVC but do they still stay high at high temperatures? Synthetic oils have much lower PVC but do they have the advantage of being much less affected by the temperature?

This Chevron patent studied how PVC changes with the temperature and found that the cam wear is directly related to the PVC100/PVC40 ratio. The closer the ratio of PVC at 100 C and PVC at 40 C is to 1, the less cam wear they observed. The GTL base oils had a PVC100/PVC40 ratio much closer to 1 than Group II oils and offered much lower cam wear, even with thinner oil.

Chevron patent on decreasing wear using GTL with PVC100/PVC40 close to one

Consideration B:

Viscosity index (VI) is an important factor in determining if the oil will stay thick when the temperatures keep rising. When pushed to their limits, bearing temperatures can easily exceed 150 C where HTHSV is measured and reported. In addition, there is still the ambiguity caused by the viscosity-index improvers (VIIs). Is it more important to have a base oil with high VI or is it OK to increase the VI using VIIs?

Consideration C:

Better the base oil (PAO, GTL, etc.), less the VIIs you need. But what do VIIs do? This paper by Timken found out that when pushed hard, VIIs may phase-transition from liquid to solid, which in turn prevents the formation of an oil film because oil cannot pass through a solid. The result is wear because there is no oil film.

High-pressure viscosity and tribology of lubricants with viscosity-modifier additives
Babak LotfizadehDehkordi, P. J. Shiller, K. K. Mistry, and G. L. Doll
Timken Engineered Surfaces Laboratories (TESL), The University of Akron, Akron OH
May 2016
(link)

PE is the polyethylene VII:

[Linked Image]

[Linked Image]


Table 1 presents that measured film thickness for PAO base oil is in agreement with estimated film thickness using Hamrock-Dowson equation. However for PAO/PE B blend by increasing contact load film thickness collapsed. This collapse correlates with the pressure-temperature sharp increase in viscosity of the specimens at 75 °C. It is also observed that after the WAM test at 75 °C of the PAO/PE mixture specimen, the fluid transformed to a semi-solid state. It is noteworthy that PAO/PEB blend demonstrated similar film thickness to the PAO and estimated film thickness using H-D equation at 40 and 100 °C.

It is not clear how the lubricants perform in the contact zone after VM phase transitions, or how the solidified VM passes through the contact, or how it functions if it does pass through the contact. However, it is likely that if VMs undergo a liquid-solid phase transition in the inlet region of the contact, the solidified material will jam or block the flow of lubricant, causing a collapse of the lubricant film. This scenario is consistent with the wear of the glass disc (Cr-coated), used in the EHL measurements. It is concluded that the plate wear arises from a collapse of the films in the contact zone. Furthermore this collapse correlates with the pressure-temperature sharp increase in viscosity of the specimens at 75 °C.


My take:

Even when leaving the additive package aside, viscosity (grade) alone is not the answer in how well an oil protects against wear because viscosity is not a single number but a function of temperature and load pressure. This gets especially more complicated with multigrade oils, where VIIs can behave unexpectedly, protecting against wear in some cases but causing wear in others. It's beneficial to have better base oils such as PAO or GTL that have higher VIs and PVCs that change less with the temperature. Better base oils such as PAO and GTL also rely less on VIIs to protect against wear, as VIIs can behave unpredictably.
 
Gohkan, a discussion of the virtual solidification of oils under Hertzian conditions is not applicable to an automotive engine (we discussed this when you were enamoured with the pressure viscosity co-efficient).

What's the maximum surface stress of an engine bearing again ???
 
Originally Posted by Shannow
Gohkan, a discussion of the virtual solidification of oils under Hertzian conditions is not applicable to an automotive engine (we discussed this when you were enamoured with the pressure viscosity co-efficient).

What's the maximum surface stress of an engine bearing again ???

It's not the oil that's solidifying here -- it's the VII polymer (polyethylene). It's also not a virtual solidification. It's a real phase transition from a liquid to a solid.

The effect only happened at 75 C. 200 MPa is not that high. Also, the bearings can run in the EHL regime as lower and lower viscosities are used. Of course, the valvetrain always runs in the EHL or boundary region.

The general point is that VIIs can behave unpredictably in relation to their protection against wear. This has been observed very early on and documented in James A. Spearot's book on HTHSV.
 
Originally Posted by Shannow
Originally Posted by Garak
Originally Posted by ka9mnx
I've often wondered if the increased bearing width to accommodate thinner oils didn't negatively offset the desired results of the thinner oils. Boundary and mixed, with the right additives, will always win the hydrodynamic race but running in those modes is running a fine line between success and failure in my opinion.

Someone here, likely Shannow, though I'm not trying to put him on the spot, mentioned that point before, and might be able to elaborate.


As I've stated previously, some of the Honda stuff is looking at the pistons as still somewhere to go.

My belief is that they are chasing that, even 'though they have to make the bearings that little bit less efficient.


Ford has been going with less piston skirt contact area, and anti-friction coating on the piston skirts. Minimizing ring tension to reduce friction is another trick. But going too far in those areas to reduce friction and HP lost can cause problems like piston slap and oil consumption.
 
Originally Posted by ZeeOSix
Ford has been going with less piston skirt contact area, and anti-friction coating on the piston skirts. Minimizing ring tension to reduce friction is another trick. But going too far in those areas to reduce friction and HP lost can cause priblems like piston slap and oil consumption.


Can definitely see that over the years, with full barrel skirts turning into "G String" looking things, anti friction coatings, fatigue of the skirt "tongues", and as you say piston slap and partial skirt collapse.

Pendulums, when intent is applied regularly go too far.
 
Originally Posted by KrisZ
I always love reading the claims about tighter clearances, even better, tighter tolerances when it comes to oil viscosity choice. These two seem to always get tighter and tighter, but nobody ever bothers to mention just hom much tighter they are from the previous engines. It's just always "tighter", as if tighter was always better.

All one can do is pretty much laugh at most of that nonsense and let the ignorant stay ignorant.

Well let me help you out. Tolerances, actually, haven't changed all that much. What has changed is machining practices and equipment. With that said, if a tolerance is +X to -X modern practices are able to keep the tolerance closer to the center of +X and -X. Tolerances probably haven't changed over the years but machining to sweet spot has. Bearing clearance may dictate oil grade recommendation but tolerance does not.
 
Originally Posted by Shannow
Originally Posted by Garak
Originally Posted by ka9mnx
I've often wondered if the increased bearing width to accommodate thinner oils didn't negatively offset the desired results of the thinner oils. Boundary and mixed, with the right additives, will always win the hydrodynamic race but running in those modes is running a fine line between success and failure in my opinion.

Someone here, likely Shannow, though I'm not trying to put him on the spot, mentioned that point before, and might be able to elaborate.


As I've stated previously, some of the Honda stuff is looking at the pistons as still somewhere to go.

My belief is that they are chasing that, even 'though they have to make the bearings that little bit less efficient.

Honda and probably all the other manufacturers. From what my old, tired and limited brain can hold, piston and ring friction accounts for 40%. From my reading and your charts.
 
Originally Posted by Shannow
Originally Posted by ZeeOSix
Ford has been going with less piston skirt contact area, and anti-friction coating on the piston skirts. Minimizing ring tension to reduce friction is another trick. But going too far in those areas to reduce friction and HP lost can cause priblems like piston slap and oil consumption.


Can definitely see that over the years, with full barrel skirts turning into "G String" looking things, anti friction coatings, fatigue of the skirt "tongues", and as you say piston slap and partial skirt collapse.

Pendulums, when intent is applied regularly go too far.


Yup, see GM's slappers as an example of what bulk-fit pistons and pornstar skirts yields.
 
Originally Posted by ZeeOSix
Originally Posted by Shannow
Originally Posted by Garak
Originally Posted by ka9mnx
I've often wondered if the increased bearing width to accommodate thinner oils didn't negatively offset the desired results of the thinner oils. Boundary and mixed, with the right additives, will always win the hydrodynamic race but running in those modes is running a fine line between success and failure in my opinion.

Someone here, likely Shannow, though I'm not trying to put him on the spot, mentioned that point before, and might be able to elaborate.


As I've stated previously, some of the Honda stuff is looking at the pistons as still somewhere to go.

My belief is that they are chasing that, even 'though they have to make the bearings that little bit less efficient.


Ford has been going with less piston skirt contact area, and anti-friction coating on the piston skirts. Minimizing ring tension to reduce friction is another trick. But going too far in those areas to reduce friction and HP lost can cause problems like piston slap and oil consumption.


My 2010 5.3L was purchased new and well maintained … had the coated skirts but that engine still had piston slap.
My new gen 5.3L's (2017/2018) do not … very quiet even on 0w20 … one change has been piston oil jets.
To use your word … they might "cushion" enough to eliminate the slap …
 
Originally Posted by 4WD

My 2010 5.3L was purchased new and well maintained … had the coated skirts but that engine still had piston slap.
My new gen 5.3L's (2017/2018) do not … very quiet even on 0w20 … one change has been piston oil jets.
To use your word … they might "cushion" enough to eliminate the slap …


It's always been a crap shoot with short skirt bulk-fit pistons. The coated and revised skirts were designed to help but it's still possible to get one that's a bit on the loose side and then it makes noise.
 
Originally Posted by Shannow
Originally Posted by StevieC


This is complete Nonsense and you know it.


Study of synthetic 5W30s...no 4 on their page of technical reports
https://www.amsoil.com/lit/g3115.pdf

Oils, as can be found currently on their site...note "applications" rather than "specifications met"
https://www.amsoil.com/lit/international/databulletins/I3405_P400.pdf
https://www.amsoil.com/lit/databulletins/g3395.pdf
https://www.amsoil.com/lit/databulletins/g3418.pdf
https://www.amsoil.com/lit/databulletins/g2133.pdf
https://www.amsoil.com/lit/databulletins/G3114.pdf
https://www.amsoil.com/lit/databulletins/g27.pdf

For some relatively "fresh" data sheets, as I said...it's in their blood...




Because this line of oils isn't officially licensed either by the API or officially certified by the manufacturer that sets the spec. Like GM's D1G2 or Chrysler MS-6395. So they can only put "applications" rather than "specifications met".
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Gohkan,

Just wanted to touch on your one point about VII's

In Amsoil's case for their Signature Series, they don't use a lot of VII's or any at all depending on the multi-weight formulation and rely on quality base oils instead for the properties they are looking for. I confirmed this by AMSOIL's technical line in an e-mail. They will confirm it for anyone that asks. Although it is further confirmed on the extended drain intervals we see where the oil's properties hasn't changed much from original.
 
Last edited:
Originally Posted by ka9mnx
Originally Posted by KrisZ
I always love reading the claims about tighter clearances, even better, tighter tolerances when it comes to oil viscosity choice. These two seem to always get tighter and tighter, but nobody ever bothers to mention just hom much tighter they are from the previous engines. It's just always "tighter", as if tighter was always better.

All one can do is pretty much laugh at most of that nonsense and let the ignorant stay ignorant.

Well let me help you out. Tolerances, actually, haven't changed all that much. What has changed is machining practices and equipment. With that said, if a tolerance is +X to -X modern practices are able to keep the tolerance closer to the center of +X and -X. Tolerances probably haven't changed over the years but machining to sweet spot has. Bearing clearance may dictate oil grade recommendation but tolerance does not.


Tolerances aren't pulled out of a hat and then let the supplier do the machining to the "sweet spot". It sounds like you need some help understanding how GD&T works.
 
Originally Posted by StevieC
Gohkan,

Just wanted to touch on your one point about VII's

In Amsoil's case for their Signature Series, they don't use a lot of VII's or any at all depending on the multi-weight formulation and rely on quality base oils instead for the properties they are looking for. I confirmed this by AMSOIL's technical line in an e-mail. They will confirm it for anyone that asks. Although it is further confirmed on the extended drain intervals we see where the oil's properties hasn't changed much from original.

Temporary oil shear, from which approximate VII content can be inferred (closer the A_Harman index to 1, less the VII content):

Mobil 1 EP 0W-20 A_Harman index = 0.94
Mobil 1 AFE 0W-20 A_Harman index = 0.93
Mobil 1 AP 0W-20 A_Harman index = 0.90 or greater (actual HTHSV unknown, minimum assumed)
Pennzoil Platinum 0W-20 A_Harman index = 0.90 or greater (actual HTHSV unknown, minimum assumed)
Amsoil SS 0W-20 A_Harman index = 0.90

Mobil 1 AP 5W-20 A_Harman index = 0.98
Mobil 1 EP 5W-20 A_Harman index = 0.94
Mobil 1 5W-20 A_Harman index = 0.94
Pennzoil Platinum 5W-20 A_Harman index = 0.92 or greater (actual HTHSV unknown, minimum assumed)
Amsoil SS 5W-20 A_Harman index = 0.92
 
Originally Posted by KrisZ
Originally Posted by ka9mnx
Originally Posted by KrisZ
I always love reading the claims about tighter clearances, even better, tighter tolerances when it comes to oil viscosity choice. These two seem to always get tighter and tighter, but nobody ever bothers to mention just hom much tighter they are from the previous engines. It's just always "tighter", as if tighter was always better.

All one can do is pretty much laugh at most of that nonsense and let the ignorant stay ignorant.

Well let me help you out. Tolerances, actually, haven't changed all that much. What has changed is machining practices and equipment. With that said, if a tolerance is +X to -X modern practices are able to keep the tolerance closer to the center of +X and -X. Tolerances probably haven't changed over the years but machining to sweet spot has. Bearing clearance may dictate oil grade recommendation but tolerance does not.


Tolerances aren't pulled out of a hat and then let the supplier do the machining to the "sweet spot". It sounds like you need some help understanding how GD&T works.

Probably because I don't know what GD&T means...
 
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