Curious about VI and MRV

[Garak]

Originally Posted By: Shannow
The 15W-40 at -40 is not reflective of start-up wear, but of inappropriate oil for the conditions increasing wear.

Or use an SAE 40. If you can't turn it over, there's no wear.

 

[Tucson Five-O]

CATERHAM,

I was referring to the most recent SOPUS Product Data Sheet (at least that I can find). It listed Pennzoil Platinum 5w-30 VI as 177 with a NOACK of 12.8.

I believe PQIA's figures of 171 with a NOACK of 9.3 as indicative of GTL being added to the base oils, a reformulation of sorts. Even PP's cousin, QSUD, has a similar VI and an even lower 8.8 NOACK!

But this illustrates my point even better. As GTL has been added to the mix regarding all of SOPUS synthetic oils to some degree, the VI has gone down slightly not up.

I am suggesting that, and you of all people along with guys like Jim Allen, have the capability of measuring oil pressure and mapping it to different oil temperatures, theory and Widman viscosity calculators be da**ed! I realize you have much experience with blending TGMO or Sustina with M1 0W-40 in varying percentages, and witnessing varying oil pressure as you make the blend lighter or heavier. I got that and acknowledge that. I am referring to "out of the bottle" formulations available, such as PU, PP, QSUD, M1 EP, Castrol EP, etc. that have slightly lower SN/GF-5 VIs than their predecessors.

More specifically, I am postulating that these modern, latest formulation oils are not any heavier in an engine anywhere below 40C down to their impressive MRV values than the older Group III oils with higher VIs.

You have the oil pressure and oil temperature gauges. Let's stop with the higher VI oils are always better and do some testing!! To be fair, I would like it if it was as simple as the higher the VI, the lower the KV is below 40C, all the way down to MRV territory, but again my hunch says that is not necessarily correct.

Let's figure out a way to test this in an engine that doesn't go into bypass until over 70-80psi, so that we have some room to test some relatively low vs. high VI 5w-30 synthetic oils and see how they map, pressure vs. temperature, ignoring the theoretical KV calculations, once and for all.

Have a great evening,
Gary

 

[OVERKILL]

Originally Posted By: Tucson Five-O
Overkill,

For a little clarification, I was thinking about PU 5W-30 (US version) when I commented on how it has a relatively low MRV compared to its SOPUS cousins with a not so great 165VI with an MRV of 9000 @ -35C, compared to Pennzoil Platinum (presumably lower GTL content) which has a 177 published VI in 5W-30 and an MRV of 13,300 @ -35C, or Quaker State Ultimate Durability with its 174VI and 14,700 MRV @ -35C.

So, in summary I am not convinced that KV calculations from a VI from 40-100C, tells us much about how thick an oil acts in an engine much below 0C, particularly with some of the newer synthetic base oils such as GTL, or Group III+ base oils such as XOM's Visom.

Gary


And that supports what I've read with respect to viscosity calculators not being accurate below 0C.

 

[Jeffs2006EvoIX]

Some very interesting posts. Thanks everyone.

So when does MRV values tend to have more impotence over VI? Right now outside my house it's 27F so my M1 0w40 in the crank of my VW siting outside is fine. If I drove to my nieces house in North Dakota where it is 5F as the high getting down to minus 20 to 30F at night I shouldn't use M1 0w40?

At this time what 502 approved oils would be adequate? Where is the line crossed when MRV values take over as to what oil to use?

Hope I'm not confusing anyone just trying to learn from you guys.

Thanks.

Jeff

 

[Quattro Pete]

Originally Posted By: Jeffs2006EvoIX
If I drove to my nieces house in North Dakota where it is 5F as the high getting down to minus 20 to 30F at night I shouldn't use M1 0w40?

At this time what 502 approved oils would be adequate?

I doubt you'll find a significantly better cold performing 502.00 oil than M1 0w-40. If I lived in ND and my car called for 502.00 oil, I would have no problem using M1 0w-40 year round.

You would have to move away from the 502.00 spec in order to find a better severe cold performing oil.

 

[OVERKILL]

Originally Posted By: Jeffs2006EvoIX
Some very interesting posts. Thanks everyone.

So when does MRV values tend to have more impotence over VI? Right now outside my house it's 27F so my M1 0w40 in the crank of my VW siting outside is fine. If I drove to my nieces house in North Dakota where it is 5F as the high getting down to minus 20 to 30F at night I shouldn't use M1 0w40?

At this time what 502 approved oils would be adequate? Where is the line crossed when MRV values take over as to what oil to use?

Hope I'm not confusing anyone just trying to learn from you guys.

Thanks.

Jeff



MRV and CCS, as others have mentioned, are more important as you begin to approach the temperatures they are measured at. So for a 0w-xx, -40C and -35C (MRV and CCS respectively). For a 5w-xx, they are measured at -35C and -30C, for a 10w-xx, -30C and -25C....etc. I think you get the picture.

Just to give you an example as to how this works:

PU 0w-40 (not approved for your application):
MRV @ -40C: 22,500cP
CCS @ -35C: 5,700cP

PU 5w-40 (approved for your application):
MRV @ -35C: N/A
CCS @ -30C: 6,200cP

QS 5w-40 (approved for your application):
MRV @ -35C: 12,800cP
CCS @ -30C: 6,280cP

To compare the 0w-40 here to the 5w-40 lubricants, you need to roughly double the figures. So we end up with (approximated of course):

PU 0w-40:
MRV @ -40C: 22,500cP
CCS @ -35C: 5,700cP

PU 5w-40:
MRV @ -40C: N/A
CCS @ -35C: 12,400cP

QS 5w-40:
MRV @ -40C: 25,600cP
CCS @ -35C: 12,560cP

Here you can see the 0w-40 having a distinct advantage. Now the MAXIMUM viscosity for CCS @ -35C for an oil to be classified as a 0w-xx is 6,200cP, so you can see why the 5w-40's are 5w-40's

What this also means is that we KNOW that M1 0w-40 has a CCS of
What that means in the context of this thread is that you probably won't find another oil that will perform as well as M1 0w-40 at these temperatures unless you find some older SM or SL bottles of M1 0w-40, LOL!

 

[Jeffs2006EvoIX]

Thanks OVERKILL now it's making sense. M1 CCS can't exceed 6200 or it couldn't be a 0w. The MRV is 31000 so that equates to 6200 CCS possibly?

Well then with that in mind the M1 does indeed seen like the best choice. I have been using it the past 2 oil changes and have no complaints of engine noise mpg loss or anything. Being $25 for 5qts at wallyworld is just icing on the cake.

Thanks for the help in the matter.

Jeff

 

[OVERKILL]

Originally Posted By: Jeffs2006EvoIX
Thanks OVERKILL now it's making sense. M1 CCS can't exceed 6200 or it couldn't be a 0w. The MRV is 31000 so that equates to 6200 CCS possibly?

Well then with that in mind the M1 does indeed seen like the best choice. I have been using it the past 2 oil changes and have no complaints of engine noise mpg loss or anything. Being $25 for 5qts at wallyworld is just icing on the cake.

Thanks for the help in the matter.

Jeff


Jeff:

Remember, MRV and CCS are measured at two different temperatures. With the MRV being 31,000cP (limit is 60,000cP and it used to be in the low 20's for the Canadian SM version FWIW) I suspect that this is also the reason for it no longer sporting a -54C pour point. That said, this means the oils is safe to use down to -40C, but where it really shines is -35C and above, as its CCS performance (being less than 6,200cP @ -35C) dictates.

So reverse our examples:

Let's say M1 0w-40 has a CCS of 5,800cP at -35C (we don't know what is is, but we know it is less than 6,200cP).

To roughly estimate what it would be at -30C, we cut that number in half, giving us 2,900cP. Compared to PU 5w-40 at 6,200cP at this temperature, you can see that the 0w-40 has a marked advantage! If we halve both of those again, that means that at -25C (-13F) M1 0w-40 is 1,450cP whilst PU 5w-40 is 3,100cP. Again, a pretty significant difference! Halve them again and at -20C (-4F) we have M1 0w-40 at 725cP and PU 5w-40 at 1,550cP. Not sure how well this halving technique scales as we get away from the measured CCS/MRV points but if we pretend that it scales well up to 0C, we could extrapolate further and say at -15C (5F) that M1 0w-40 is 363cP, whilst PU 5w-40 is 775cP.....etc. You get the idea I'm sure.

 

[edyvw]

After temperature of -21c in Colorado Springs last week, I am definitely going back from M1 to GC!

 

[OVERKILL]

Originally Posted By: edyvw
After temperature of -21c in Colorado Springs last week, I am definitely going back from M1 to GC!


The CCS of GC is 5,950cP @ -35C. I doubt it is any thinner than M1 0w-40.

 

[edyvw]

Well, what I have observed in cold temperatures is that GC has much smoother start. Every time I start engine with M1 I can hear camshaft! That never happens with GC unless, car is not driven for 3-4 days. What I think is that GC has magnetic technology also, that is popular in Europe so molecules sticks to camshaft longer.
Anyway, I get what you saying about number, however in practice, it is different story!
I am kicking out this M1 at 3K, and going back to good ole GC!

 

[Quattro Pete]

It's been a while since I used GC in my 530i, but I think I remember that after sitting in near 0F weather, the engine was harder to start (slower turn over) with GC in it than with PU 5w-40.

 

[CATERHAM]

Originally Posted By: OVERKILL
Originally Posted By: Jeffs2006EvoIX
Some very interesting posts. Thanks everyone.

So when does MRV values tend to have more impotence over VI? Right now outside my house it's 27F so my M1 0w40 in the crank of my VW siting outside is fine. If I drove to my nieces house in North Dakota where it is 5F as the high getting down to minus 20 to 30F at night I shouldn't use M1 0w40?

At this time what 502 approved oils would be adequate? Where is the line crossed when MRV values take over as to what oil to use?

Hope I'm not confusing anyone just trying to learn from you guys.

Thanks.

Jeff



MRV and CCS, as others have mentioned, are more important as you begin to approach the temperatures they are measured at. So for a 0w-xx, -40C and -35C (MRV and CCS respectively). For a 5w-xx, they are measured at -35C and -30C, for a 10w-xx, -30C and -25C....etc. I think you get the picture.

Just to give you an example as to how this works:

PU 0w-40 (not approved for your application):
MRV @ -40C: 22,500cP
CCS @ -35C: 5,700cP

PU 5w-40 (approved for your application):
MRV @ -35C: N/A
CCS @ -30C: 6,200cP

QS 5w-40 (approved for your application):
MRV @ -35C: 12,800cP
CCS @ -30C: 6,280cP

To compare the 0w-40 here to the 5w-40 lubricants, you need to roughly double the figures. So we end up with (approximated of course):

PU 0w-40:
MRV @ -40C: 22,500cP
CCS @ -35C: 5,700cP

PU 5w-40:
MRV @ -40C: N/A
CCS @ -35C: 12,400cP

QS 5w-40:
MRV @ -40C: 25,600cP
CCS @ -35C: 12,560cP

Here you can see the 0w-40 having a distinct advantage. Now the MAXIMUM viscosity for CCS @ -35C for an oil to be classified as a 0w-xx is 6,200cP, so you can see why the 5w-40's are 5w-40's

What this also means is that we KNOW that M1 0w-40 has a CCS of
What that means in the context of this thread is that you probably won't find another oil that will perform as well as M1 0w-40 at these temperatures unless you find some older SM or SL bottles of M1 0w-40, LOL!

Sticking to 502 oils does limit Jeff's options.
There are some European high VI 0W-30 oils on the 502 list that are lighter than M1 0W-40 on start-up but they are not readily available and of course are more expensive.
One cost effective way to run a lighter oil primarily on start-up is to use M1 0W-40 but top up with a 0W-20 like TGMO. Adding as much as 25% TGMO will still give you with a HTHSV of 3.5cP with a VI over 190. It can be done and still comply with your warranty if that's your concern.

 

[CATERHAM]

Originally Posted By: Quattro Pete
It's been a while since I used GC in my 530i, but I think I remember that after sitting in near 0F weather, the engine was harder to start (slower turn over) with GC in it than with PU 5w-40.

That would have been the prior lighter version of PU 5W-40 with the 180 VI and HTHSV of 3.68cP.
I am certain that wouldn't be the case with the current PU 5W-40 with a 165 VI and HTHSV of 3.88cP.

 

[edyvw]

Originally Posted By: Quattro Pete
It's been a while since I used GC in my 530i, but I think I remember that after sitting in near 0F weather, the engine was harder to start (slower turn over) with GC in it than with PU 5w-40.

When I used once PU 5W40 (SM version) in Passat 1.8T it had rougher start then GC.
Regardless, I gave another shot to M1, moving to Colorado, however, this is the end of trying to find some reason to use M1.
If I decide to go with 40 weight, it will be PU or Motul.

 

[OVERKILL]

Originally Posted By: edyvw
Well, what I have observed in cold temperatures is that GC has much smoother start. Every time I start engine with M1 I can hear camshaft! That never happens with GC unless, car is not driven for 3-4 days. What I think is that GC has magnetic technology also, that is popular in Europe so molecules sticks to camshaft longer.
Anyway, I get what you saying about number, however in practice, it is different story!
I am kicking out this M1 at 3K, and going back to good ole GC!


Sounds like the marketing folks have gotten to you. GC doesn't have "magnetic technology", it probably has some esters in it (that are polar and cling to metal) just like Mobil uses in probably all of their oils.

What causes the sound difference could be one of the additives Castrol uses and perhaps Mobil doesn't. Mobil uses tri-nuclear moly for example, maybe Castrol uses something else that works to deaden sound on your particular engine?

My M5 doesn't care and makes no clatter on PU 5w-40 currently, even though it is significantly heavier than what I had in there last winter (M1 0w-40, which it also made no noise on).

So I would argue that "in practice" your statement about the numbers being a "different story" is more that your engine exhibits certain acoustic traits on M1 0w-40 that it doesn't on GC. There's nothing wrong with pointing that out. But it doesn't change the fact that GC likely isn't any thinner at -35C than M1 0w-40 is. And at higher temps, again, M1 0w-40, due to having a higher VI, is also thinner

 

[CATERHAM]

With all the research done on GC, it was once a BITOG darling, has it's MRV and CCS spec's ever been determined?
I don't think so.
That said I would think being a PAO based oil it's MRV and CCS spec's would be better than M1 SN 0W-40 which is now a GP III, AN based oil in NA and most countries. M1 SN 0W-40's MRV of 34,000cP is not great and I don't think Mobil or the OEMs in which it is a FF care either. What's more important is how light it is on start-up at more typical cold start-up temp's and it's high VI has more to do with that.

 

[Jeffs2006EvoIX]

In theory though wouldn't one expect a 0w30 to be "lighter" than a 0w40?

I Have considered GC but felt the slightly higher hths of the M1 would be best in forced induction motor like the TSI 2.0 in my VW. Especially wherei live where summer temps get around 120F.

As for cold flow where I live it gets in the 20's F Range so the M1 should be more than adequate.

GC Though for some reason maybe it's the fact it's from Germany ha ha. I Have always been tempted to try it.

I Just dislike changing brands often. I like to just stick with something and that is that.

Would be nice if we can get more actually specs on GC. M1 has good info on their site. Penzoil and Castrol sites are kinda a joke actually.

Jeff

 

[Shannow]

Originally Posted By: CATERHAM
With all the research done on GC, it was once a BITOG darling, has it's MRV and CCS spec's ever been determined?
I don't think so.


http://www.castrol.com/liveassets/bp_internet/castrol/castrol_usa/STAGING/local_assets/downloads/p,q/Edge_BLACK_PDS_Sept_2011.pdf

 

[Quattro Pete]

Originally Posted By: Shannow
Originally Posted By: CATERHAM
With all the research done on GC, it was once a BITOG darling, has it's MRV and CCS spec's ever been determined?
I don't think so.


http://www.castrol.com/liveassets/bp_internet/castrol/castrol_usa/STAGING/local_assets/downloads/p,q/Edge_BLACK_PDS_Sept_2011.pdf

Sadly these aren't the actual MRV and CCS figures. They are just the maximums as required by API/SAE in order to qualify for the 0W rating.