High V.I. oils, on purpose, or consequence??

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There's something else perhaps I should mention...

I said earlier in this thread that in all my years formulating engine oil, I hardly ever bothered looking at oil Viscosity Index. Well the same is true about whether lubrication is hydrodynamic or boundary or whatever! A Stribeck curve? What's one of those when it's at home?? It wasn't just me either. None of my colleagues or customers ever talked this particular language. It just didn't come up...ever...

Sorry to dispel another cherished myth but best you know the truth about how the slippery stuff is put together.
 
Joe90_guy,
as a mechanical engineer, I would expect that you never used on also.

It's my job to design the component, operational speed/load, clearances and alignments and lubricant parameters (viscosity, temperature, FM, and AW) to suit where I either put it on the Stribeck (or sommerfeld) curves, or where it ends up in a multi parameter casing.
 
Originally Posted By: Gokhan
Good reading on Infineum's SV line of VIIs. They are great additives and improve the oil in many ways:

http://www.infineuminsight.com/insight/jun-2013/satisfying-both-sides-of-the-equation


The first thing you need to understand about Infineum (and Paramins which came before it) is that first, second and third, they are a MARKETING company. I am not saying their juice is particularly bad but every bit of technical blurb they issue comes ready-coated with a thick layer of verbal varnish. It's their job to sell additive so this is to be expected.
My advice is you should not explicitly believe every thing you read and all that glitters is not gold.
 
Some good input and good to see finally there are people who ignore VI.

In my view it is a complete consequence of the VII choice and amount, You can get ridiculous high VI numbers using PMA however they are dirty and cause deposits. Hence why only 0W-20s tend to use them

I don't ever hear anyone even talk about VI. In my mind it is largely irrelevant but a factor 'PDS people' like to use.

Some of the Europe oils now are seeing over 200 VI but this is due to a new VII type that has started to be used. The best base oils out there are around 150 VI max.
 
Originally Posted By: bobbydavro
Some good input and good to see finally there are people who ignore VI.



The VI thing is really way-way over-hyped by oil companies ...... and sing along real loud in Bitog here.

An operating viscosity of 40 cSt in a VI 9x oil(of say 80W90) offers far better components protection than a VI 2xx (of say 75W90 at premium price) operating at 39.x cSt ...............every other things being equal.
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Edit: grammar
 
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Originally Posted By: zeng


The VI thing is really way-way over-hyped by oil companies ...... and sing along real loud in Bitog here.


I think it's hyped more here than by the oil companies.
 
Originally Posted By: Shannow


Boutique oils like Amsoil ACD are straight grades with multigrade characteristics. ACD is a straight 30 that does 10W30 as well, and has an inherent HTHS of 3.4...

OK, just say you got some ACD straight 30, which is 10W30, and you added some VIIs to it.

The viscosity at 100C would go up, so it would become something like at 10W40, and the VI would go up too.

Would the cold performance change much? Would it still be a 10W

Would the HTHS change much from the original 3.4 ?
 
Originally Posted By: Joe90_guy
There's something else perhaps I should mention...

I said earlier in this thread that in all my years formulating engine oil, I hardly ever bothered looking at oil Viscosity Index. Well the same is true about whether lubrication is hydrodynamic or boundary or whatever! A Stribeck curve? What's one of those when it's at home?? It wasn't just me either. None of my colleagues or customers ever talked this particular language. It just didn't come up...ever...

Sorry to dispel another cherished myth but best you know the truth about how the slippery stuff is put together.


You keep saying you didn't pay attention to this or that when you were formulating oils.

What did you pay attention to?
 
Originally Posted By: demarpaint
Originally Posted By: zeng


The VI thing is really way-way over-hyped by oil companies ...... and sing along real loud in Bitog here.


I think it's hyped more here than by the oil companies.


I agree!
 
Originally Posted By: A_Harman
Originally Posted By: Joe90_guy
There's something else perhaps I should mention...

I said earlier in this thread that in all my years formulating engine oil, I hardly ever bothered looking at oil Viscosity Index. Well the same is true about whether lubrication is hydrodynamic or boundary or whatever! A Stribeck curve? What's one of those when it's at home?? It wasn't just me either. None of my colleagues or customers ever talked this particular language. It just didn't come up...ever...

Sorry to dispel another cherished myth but best you know the truth about how the slippery stuff is put together.


You keep saying you didn't pay attention to this or that when you were formulating oils.

What did you pay attention to?


Probably meeting the requirements of the various specifications, passing engine tests and making sure the oil was didn't fall apart.
 
So I'm late to the party - again!!

Too bad because this is the kind of BITOG discussion that I really enjoy. As far as my opinion goes (since it's been asked for a couple of times):
  • I agree with Joe - no formulator focuses on VI *unless a marketer specifically asks for it.
  • The most common VM's for engine oils are OCP's and some PMA's (Although I've also seen some Styrenic Polymers used where deposits and shear stability are required)
  • Joes' comments on VM's and deposits are a good example. Most formulators choose their VM based off of blending complexity, shear stability requirements and deposit control.
  • Dispersant Viscosity Modifiers are not commonly used in engine oils - although I expect we may see them incorporated in some of the new PC-11/GF-6 engine oils.
  • There is wide range of options for formulators making boutique engine oils with extremely high VI. This is a trend we often see in hydraulics with a lot of hydraulic oil now calling for VI of around 230 (and no, these are not always synthetics.)
  • as Molakule said, typically an XHVI engine oil is typically a result of high quality base oils (which when discussing Group II vs Group III - VI is the defining characteristic) as well as the top tier VM's.


So to answer this question:
Quote:
Are the very high (> 200) viscosity indexes we are seeing on some select oils actually BLENDED ON PURPOSE to get these levels, or are they merely a consequnce of the blenders trying to reach other goals for their final product?? shrug

I would say it depends on the marketer, but more often a consequence of a number of factors over starting with the goal of a XHVI. It's more often that after the base formula is complete that there may be a conversation about VI between the formulators and the marketing team, because of a perceived market advantage.
 
Originally Posted By: A_Harman
Originally Posted By: Joe90_guy
There's something else perhaps I should mention...

I said earlier in this thread that in all my years formulating engine oil, I hardly ever bothered looking at oil Viscosity Index. Well the same is true about whether lubrication is hydrodynamic or boundary or whatever! A Stribeck curve? What's one of those when it's at home?? It wasn't just me either. None of my colleagues or customers ever talked this particular language. It just didn't come up...ever...

Sorry to dispel another cherished myth but best you know the truth about how the slippery stuff is put together.


You keep saying you didn't pay attention to this or that when you were formulating oils.

What did you pay attention to?


I would say two things...cost and managing completely unrealistic expectations!

Big apologies to all those folks out there that think engine oil formulation is all about wearing white coats and staring down microscopes all day! The reality is that a formulator has to deliver the maximum bang for the minimum buck for the least test spend. You also have to be prepared to gamble huge sums of money and in this regard, it helps if you're clever but it's essential that you are extremely lucky. You have to contend with a lot of 'we want this (latest & greatest) spec in these (garbage) base oils with this (cheapo) VII and the DI treat cannot be above this (absurdly low) level and we don't want you to use more than this (absurdly low) level of high quality base oil and by the way, we're expecting you to pick up the (eye-wateringly high & open ended) cost of the development programme and could you have it all done and dusted in three months time?

You can usually spot an oil formulator at twenty paces. He's the one that curses the most and has no friends...
 
Originally Posted By: Joe90_guy
In response to the various posts that came in while I was asleep...

If you look at the PDS of the D-VII you quoted, you will read the words 'suited to automatic transmission fluids and tractor hydraulic fluid formulations'. Draw your own conclusions.


The poster, as I understood his post, was using the additive as an example of how viscosity modififers can assist cleaning.

Originally Posted By: Joe90_guy
If you properly understand how engine oil componentry blends, you get to realise that, all things being equal, adding low percentages of an extremely heavy stock makes for WORSE volatility, higher levels of conventional VII use and a concomitant worsening of the oils shearability. It's one of those counter-intuitive things that takes a while to get your head around.


I disagree. Adding a higher viscosity PAO, and especially adding the mPAO oils have an advantage to those conditions I mentioned above.
 
Molekule,

I'm guessing you have access to a lab that can measure KV100, CCS & Noack?
If so, can I suggest you make up a blend of conventional PAO 4 & PAO 6 and any VI of choice. Organise the blend to meet some arbitrary KV100 and CCS targets. Measure the NOACK.
Make up a second blend of PAO 4 and any whatever heavy mPAO takes your fancy along with the same VI. Organise the blend to give you exactly the same KV100 and CCS you had before. Measure the NOACK.
I will bet you a penny to a pinch of salt that the NOACK volatility goes up because narrow cut volatility is always lower than a dumb bell blend of equal viscometrics.

PS - might you know a Brit called Dave Gray?

PPS - I not free to comment on certain products such as the one the poster posted.
 
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Originally Posted By: Joe90_guy

Big apologies to all those folks out there that think engine oil formulation is all about wearing white coats and staring down microscopes all day! The reality is that a formulator has to deliver the maximum bang for the minimum buck for the least test spend. You also have to be prepared to gamble huge sums of money and in this regard, it helps if you're clever but it's essential that you are extremely lucky. You have to contend with a lot of 'we want this (latest & greatest) spec in these (garbage) base oils with this (cheapo) VII and the DI treat cannot be above this (absurdly low) level and we don't want you to use more than this (absurdly low) level of high quality base oil and by the way, we're expecting you to pick up the (eye-wateringly high & open ended) cost of the development programme and could you have it all done and dusted in three months time?

You can usually spot an oil formulator at twenty paces. He's the one that curses the most and has no friends...



LOL
crackmeup2.gif


This is priceless! Especially because it gives me a mental image of it.
 
Quote:
You can usually spot an oil formulator at twenty paces. He's the one that curses the most and has no friends...


I know a guy exactly like this - spot on!
cheers3.gif
 
Originally Posted By: Joe90_guy
Molekule,

I'm guessing you have access to a lab that can measure KV100, CCS & Noack?
If so, can I suggest you make up a blend of conventional PAO 4 & PAO 6 and any VI of choice. Organise the blend to meet some arbitrary KV100 and CCS targets. Measure the NOACK.
Make up a second blend of PAO 4 and any whatever heavy mPAO takes your fancy along with the same VI. Organise the blend to give you exactly the same KV100 and CCS you had before. Measure the NOACK.
I will bet you a penny to a pinch of salt that the NOACK volatility goes up because narrow cut volatility is always lower than a dumb bell blend of equal viscometrics.

You might be right about the NOACK volatility - but to be honest I hate that test. The variability and reproduce-ability issues are enough to drive anyone insane - I'm curious about your opinion on it?

I've seen the mPAO's used in similar ways to bright stock for synthetic formulas. I don't think a straight out replacement of PAO 6 in a formula would provide many benefits (dependent on the formula of course.)
 
Solarent,

The thing that a lot of folks don't get is that any discussion of reducing Noack has to be put within the straight jacket of 'equal viscometrics'. It's just not enough to say 'this is heavy and good so it will do the job'. Also let's not forget that conventional PAO 40 (KV100C about 40 cst) has been knocking about for decades and no-one to my knowledge has ever thought it's a smart idea to plop it into a crankcase oil so what's the big deal with mPAO??

Oh and yes, Noack is a bit skanky as a test. The US has their Simulated Distillation equivalent which is probably a bit better in terms of repeatability. Sadly neither test really tells you what you want to know about oil whose volatility over the life of an oil drain can be far worse than either test would suggest.
 
I see your point.

XOM in their formulation guide suggest using mPAO as a way to boost HTHS at relatively low treat rates (~5%). They also suggest it as a way to boost VI. Interestingly they make no mention of improving volatility.
 
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