Use 10W-20 as a replacement for XW-20 and XW-30 applications?

[OhioTech]

Where does the ILSAC GF-x spec specify a minimum HTFS (Full shear) to pass? What oil specs actually define a HTFS spec to pass? And what ASTM and/or SAE spec procedure and test machine do they use?

Got any links to the official documentation?

They don’t recommend an HTFS. They added a timing chain wear test on a 2.0 EcoBoost, and that was the result - with the bare minimum add packs used in shelf oils - the SP formulations ended up with slightly thicker base oils to pass the test.

Race to the bottom, cheapest way out…

 

[SubieRubyRoo]

Why do you need a 10w20

In locations that never see temps below maybe -10F, a 10w20 provides sufficient cold performance but with none of the downsides of viscosity index improvers nor very thin base oils.

This basically trades a little cold temperature performance that’s of little use in many places, for a more robust and consistent oil performance at all other times.

 

[SubieRubyRoo]

Even oils with no VII additive will have some shear thinning, and will have a lower HTFS than HTHS.

Base oils don’t shear. Kschachn has provided many references.

Also, when not pursuing the cheapest oil possible, there are very low shear VIIs available. High Performance Lubricants has shared some info here, while protecting the name/supplier of the actual VII they use to achieve these results.

As a complete guess, I would assume some of the most highly certified Euro formulations (M1 FS 0w40 comes to mind) are likely to use these better VIIs, compared to say Dollar General’s 0w20 which likely uses the cheapest and therefore most shear-prone VIIs because they are trying to hit rock-bottom price point and a given profit margin.

 

[OVERKILL]

I know, HTFS is not mentioned anywhere obviously, there is even no standard test for it. Thats actually such a shame for an industry not to have an standard on such an important merit of their product.

I mean, objectively, if you wanted to know the base oil viscosity (which is what Gokhan was trying to calculate) it's easy enough to do if you are the blender, since you know the viscosities of the bases used. It's no great mystery for those blending the oils.

The problem with trying to calculate it, as was observed, is that different base oils and VII combinations behave quite differently, so there's no accurate way to, as an outsider, work the finished product's data backwards to accurately arrive at that figure, hence it being only an estimate and an interesting, but not necessarily valuable, exercise.

I'm not sure of its importance. We have standardized testing for various conditions to establish limits and ensure compliance with those limits for wear, deposits...etc. HTHS is used by many Euro approvals and I suspect if there was actually value in knowing the base oil viscosity, they would be privy to that information as well. It's likely not on their radar because it's not important enough, and it can't be used as a metric to infer the performance of the finished product.

 

[ZeeOSix]

Base oils don’t shear. Kschachn has provided many references.

I think he meant that all oils exhibit temporary (not permanent) viscosity loss under shear. Base oils don't have permanent shear because there are no VIIs in it to beak apart from shearing. But oil without VIIs will still exhibit some temporary loss in viscosity under shear action - that's just a basic property of liquids. That's why the dynamic viscosity which is the viscosity under higher shear rates is different than the kinematic viscosity which is movement just due to flow under gravity. Dynamic viscosity is the result of shearing at higher movement speed (shear) than what gravity flow will produce. When oil flows due to gravity, the internal shear rate is basically zero compared to the dynamic viscosity shear rate realm. You can see that effect in that one graph I posted earlier comparing the KV100, HTHS and calculated HTFS data from Gokhan.

Obviously, oils with lots of VIIs will shear down temporarily even more than oils without VIIs, and they can also permanently shear to a lower viscosity as the VIIs physically break down.

 

[chris719]

There are one or two SAE papers I came across that actually demonstrated better performance with some amount of VII rather than none. Can't find them at the moment but it was interesting. I think the view that VII == bad is a bit oversimplified.

 

[Rogueman2016s]

In locations that never see temps below maybe -10F, a 10w20 provides sufficient cold performance but with none of the downsides of viscosity index improvers nor very thin base oils.

This basically trades a little cold temperature performance that’s of little use in many places, for a more robust and consistent oil performance at all other times.

I never heard of 0 or 5w20 failure stories but that’s interesting

 

[SubieRubyRoo]

There are one or two SAE papers I came across that actually demonstrated better performance with some amount of VII rather than none. Can't find them at the moment but it was interesting. I think the view that VII == bad is a bit oversimplified.

It’s no shocker that some VII would give slightly better cold properties over a similar oil with no VII, but it would be a surprise if there were wear, deposit, or other benefits. Any chance you can dig them up?

 

[DirectRejection]

There are one or two SAE papers I came across that actually demonstrated better performance with some amount of VII rather than none. Can't find them at the moment but it was interesting. I think the view that VII == bad is a bit oversimplified.

Yes. Yes. And High Peeformance Lubricants is very judicious in their usage of Viscosity Index Improvers.

 

[Fredxt]

I mean, objectively, if you wanted to know the base oil viscosity (which is what Gokhan was trying to calculate) it's easy enough to do if you are the blender, since you know the viscosities of the bases used. It's no great mystery for those blending the oils.

The problem with trying to calculate it, as was observed, is that different base oils and VII combinations behave quite differently, so there's no accurate way to, as an outsider, work the finished product's data backwards to accurately arrive at that figure, hence it being only an estimate and an interesting, but not necessarily valuable, exercise.

I'm not sure of its importance. We have standardized testing for various conditions to establish limits and ensure compliance with those limits for wear, deposits...etc. HTHS is used by many Euro approvals and I suspect if there was actually value in knowing the base oil viscosity, they would be privy to that information as well. It's likely not on their radar because it's not important enough, and it can't be used as a metric to infer the performance of the finished product.

I noticed the issue with Gokhans formula, sometimes it predicts negative VII content, e.g. HPL Euro 5w20. Of course blenders can publish that info but I see most of them don't even have the HTHS of the final product, just telling us it passes xyz test.

If we go with the sort of end to end tests, like the Mileage Accumulation Dynamometers tests, all I see is a 1846 hr test at 300hr oil changes with low highway loads. For me, at average speed of 35mph this translates to 64K miles for me at low load with 11k oil changes and not 20K. OK, the engine was in spec after the test (64K miles for me), but that does not mean much to me.

I would like to see +4000hr tests (140k miles at 35mph) were these 300hr MADs, sequence VH, Dexos 1g3, sequence 3H are performed back to back. That's what a test that will make us assured the product is good long term end-to-end.

By the way, this guy did a great job showing these tests to us:

 

[chris719]

I noticed the issue with Gokhans formula, sometimes it predicts negative VII content, e.g. HPL Euro 5w20. Of course blenders can publish that info but I see most of them don't even have the HTHS of the final product, just telling us it passes xyz test.

Yeah, in the end you can basically infer the result from KV100 vs HTHS. There seems to be a strong trend there.

 

[OVERKILL]

Yeah, in the end you can basically infer the result from KV100 vs HTHS. There seems to be a strong trend there.

mPAO totally borks the estimate functionality, as do bio base oils.

 

[chris719]

It’s no shocker that some VII would give slightly better cold properties over a similar oil with no VII, but it would be a surprise if there were wear, deposit, or other benefits. Any chance you can dig them up?

https://spiral.imperial.ac.uk/bitstream/10044/1/45361/1/Marx-N-2017-PhD-Thesis.pdf

Page 73 has a good summary of the findings of various groups.

Okrent [54,55] found in engine tests that polymer-containing oils decreased friction
compared to Newtonian mineral oils of the same viscosity at a given temperature (an
equivalent Newtonian mineral oil) [54]. To his surprise, they also decreased wear,
even though they produced lower film thicknesses than the equivalent mineral oils [54].
Furthermore, it appeared that the wear reduction was dependent on molecular weight,
blend concentration and polymer type. Later on Okrent concluded, by utilising metallic
surface adsorbing detergents, that the tested VMs must also adsorb onto the metallic
surface and thus decrease wear [55].

It's not clear that it applies to all VMs under all conditions etc.

 

[SubieRubyRoo]

https://spiral.imperial.ac.uk/bitstream/10044/1/45361/1/Marx-N-2017-PhD-Thesis.pdf

Page 73 has a good summary of the findings of various groups.

It's not clear that it applies to all VMs under all conditions etc.

Thanks… my question now of course is, do “Newtonian mineral oils” exhibit the same characteristics as the base oils used in HPL’s No VII line? Just wondering, and I doubt any of us besides @High Performance Lubricants can answer.

 

[ZeeOSix]

Thanks… my question now of course is, do “Newtonian mineral oils” exhibit the same characteristics as the base oils used in HPL’s No VII line? Just wondering, and I doubt any of us besides @High Performance Lubricants can answer.

From what I'm reading from other sources on Newtonian fluids, many are only Newtonian in the low shear rate range. As the shear rate increases, it can deviate from being Newtonian. I doubt any base oil stays perfectly Newtonian (ie the dynamic viscosity never changes at any shear rate) as the shear rate gets near or above the 1.0^6/sec rate. Maybe HPL can confirm if they have ever ran base oils through a high shear rate test machine.

 

[SubieRubyRoo]

From what I'm reading from other sources on Newtonian fluids, many are only Newtonian in the low shear rate range. As the shear rate increases, it deviated from being Newtonian. I doubt any base oil stays perfectly Newtonian (ie the dynamic viscosity never changes at any shear rate) as the shear rate gets near or above the 1.0^6/sec rate. Maybe HPL can confirm if they have ever ran base oils through a high shear rate test machine.

I forwarded the question to Dave, if I get a response that can be shared I’ll post it up.

 

[SubieRubyRoo]

I forwarded the question to Dave, if I get a response that can be shared I’ll post it up.

Quick response: no, Dave hasn’t tested base oils in that manner. It was worth a shot

 

[ZeeOSix]

Quick response: no, Dave hasn’t tested base oils in that manner. It was worth a shot

Maybe he will try it now that we have him wondering, lol.