Is 10W-30 an Obsolete Viscosity Grade?

[Bryanccfshr]

"""And to meet GF4 standards"energy conserving" both 10w30's and 5w30's must lose viscosity. It is designed in so that the oils can pass the economy test.""

Not to my knowledge EC is normally met by running vis to low end and using good FM's. There is no shear down to a percent or certain number to qualify as a EC oil. If so i'd love to see this since I have heard this ststed before BUT know of NO such verbage in the API testing. That is why a FULL syn with little to NO vis/shear reduction can qualify as a EC oil.""

It is not a "requirement" in that this aspect is not measured, what is measured is overall performance and effieciency of the oil at differnt stages of use.
Perhaps the viscosity loss is not due to ILSAC requirements but rather a result of them to pass the aged oil sequence tests. I am making an assumption(so if I am wrong on this dynamic please correct me) that friction modifiers lose effectiveness with age to reach this conclusion in theory.
In order to match the lower friction characteristics of the reference PAO's used in the sequence tests some loss in viscosity is needed as friction modifiers become less effective.
It sounds logical to me but I am not a lube oil designer..just a hapless enthusiast who is too caught up in oil

Edit to add it is sequance VIB that I am referencing and by proxy the sequence IIIGA may impact the formulation
ILSAC GF4

 

[Bryanccfshr]

The procedure is most interesting.

Sequence VIB procedure

 

[427Z06]

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"And to meet GF4 standards "energy conserving" both 10w30's and 5w30's must lose viscosity. It is designed in so that the oils can pass the economy test."

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I took your "must lose viscosity" to mean "temporary shear", or in other words, low HTHS relative to the kinematic (static) viscosity at 100°C. This also implies significant use of VIIs to achieve the lower relative HTHS. And then that implies the oil will eventually loose some kinematic (static) viscosity at 100°C as the VIIs are chewed up. Which will then prevent the increase in kinematic (static) viscosity at 100°C as the lighter fractions evaporate and the remainder oxidizes. (We're assuming dinos here.)

Full synthetics, on the other hand, may achieve their fuel economy improvement through inherent higher VI, inherent extra lubricity, coupled with the FMs. This would at least explain why something like RL doesn't produce a big fuel economy hit even though it's HTHS is higher relative to the kinematic (static) viscosity at 100°C.

Why do I feel like I just wrote something that Gary would write?

 

[rpn453]

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The public has nothing to do with it. DCX requires/recommends it for my 2006 Wrangler (4.0).

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Be very careful with the oil you use in that engine. An oil manufacturer could always take a 0W-30 or 5W-30 oil, label it as 10W-30, and your engine would be destroyed within 3000 miles! I recommend independent testing of any oil you use to ensure that it only passes the 10W tests, and not the 5W ones too.

 

[toocrazy2yoo]

427.. WHAT??

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Full synthetics, on the other hand, may achieve their fuel economy improvement through inherent higher VI, inherent extra lubricity,

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That's a rhetorical "WHAT???" btw.. All in good humor. Full Synthetics? "Inherant extra lubricity"?

I thought there IS no such thing? In Syn, you get more stamina, stability, and tolerance for heat, longer OCI, but now you're saying more slippery? That what that means, "Inherant extra lubricity"?

 

[427Z06]

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427.. WHAT??

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Full synthetics, on the other hand, may achieve their fuel economy improvement through inherent higher VI, inherent extra lubricity,

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That's a rhetorical "WHAT???" btw.. All in good humor. Full Synthetics? "Inherant extra lubricity"?

I thought there IS no such thing? In Syn, you get more stamina, stability, and tolerance for heat, longer OCI, but now you're saying more slippery? That what that means, "Inherant extra lubricity"?

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Hey...I have to check once and while to see if you guys are paying attention or not.

Lubricity, as in the elastohydrodynamic (EHD) traction coefficient and the pressure-viscosity coefficient.

 

[toocrazy2yoo]

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Hey...I have to check once and while to see if you guys are paying attention or not.

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Yeah, yeah, I almost asked you what it's like to have know-nothing mutts like me scrutinizing your posts looking for the slightest mis-speak...

 

[Gary Allan]

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Why do I feel like I just wrote something that Gary would write?

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Well ..you had enough conditional/qualifying branching in one string to surely qualify

 

[sw99]

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The public has nothing to do with it. DCX requires/recommends it for my 2006 Wrangler (4.0).

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Be very careful with the oil you use in that engine. An oil manufacturer could always take a 0W-30 or 5W-30 oil, label it as 10W-30, and your engine would be destroyed within 3000 miles! I recommend independent testing of any oil you use to ensure that it only passes the 10W tests, and not the 5W ones too.

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#@$%!! I ran 5w30 in my 242 I6 wrangler and it had over 100K on the ticker. It ran much smooter than when I first ran the reccomended 10w30. Todays dino oils are much better than the old days...

 

[Bryanccfshr]

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"
I took your "must lose viscosity" to mean "temporary shear", or in other words, low HTHS relative to the kinematic (static) viscosity at 100°C. This also implies significant use of VIIs to achieve the lower relative HTHS. And then that implies the oil will eventually loose some kinematic (static) viscosity at 100°C as the VIIs are chewed up. Which will then prevent the increase in kinematic (static) viscosity at 100°C as the lighter fractions evaporate and the remainder oxidizes. (We're assuming dinos here.)

Full synthetics, on the other hand, may achieve their fuel economy improvement through inherent higher VI, inherent extra lubricity, coupled with the FMs. This would at least explain why something like RL doesn't produce a big fuel economy hit even though it's HTHS is higher relative to the kinematic (static) viscosity at 100°C.

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That's another way to justify the Viscosity loss, due to the inherent properties of the oils. With use an oil is naturally going to move towards its foundation in propertioes. If it has 6 and 8 cst basestocks it will tend to move towards that.