Ultra 5w-20 vs Platinum 0w-20

[randomhero439]

Ultra 5w-20:
VI: 154
CCS (-30): 4000
MRV (-35): 7750
NOACK: 5.0%

Platinum 0w-20
VI: 164
CCS (-35): 5720
MRV (-40): 17700
NOACK: 8.9%

Is it just me or is Ultra 5w-20's MRV seem superior to Platinum's? I know its not a direct comparison, but is it possible to speculate that?

What would you prefer to use during winter if the coldest weather will be about 10*F at night. Seems kinda obvious that 0w-20 would be best... but given that Ultra is a Group 4 and Platinum is closer to a Group 3 it kinda complicate things.

 

[147_Grain]

Either oil is fine for cold-starts at 10*F, with PP 0W-20 having an edge at low temps. At 10*F., your engine may not notice the difference between the two oils.

PP 0W-20: http://www.epc.shell.com/Docs/GPCDOC_X_cbe_24855_key_140007466171_201212050515.pdf

PU 5W-20: http://www.epc.shell.com/Docs/GPCDOC_X_cbe_24855_key_140007304052_201207271342.pdf

 

[randomhero439]

From what ive noticed, both oils will easily pump at 10*F (MRV), but i want the one with the lowest CCS (Cold Crank Start), which im assuming is the ease of cranking. I think at that point PP 0w-20 would be better.

 

[CATERHAM]

One important viscosity spec' you've omitted is HTHSV which is 2.7cP for PU and 2.6cP for PP.
PP has the combination of a higher VI (although one of the lowest for a 0W-20 grade) and a lower HTHSV meaning it is considerably lighter at all temp's than PU.

So it really is a no-brainer choice in favour of PP 0W-20 although interestingly enough the TGMO/M1 0W-40 blend you're running will actually be lighter than PU at all start-up temp's as well as PP likely down to at least 10F.

 

[147_Grain]

PP is a little lighter on startup and a tad thicker under normal operations than PU (8.6 versus 8.4 at 100*C, cSt).

At 10*F. (-12*C.), the 0W-20 is 11% lighter than 5W-20 CCS (Cold Crank Start) is better for PP too.

 

[CATERHAM]

Yes but you forget that KV100 spec's do not correlate well with operational viscosity and say more about an oil's chemistry than everything else. Remember HTHSV trump's KV100. That in conjunction with the higher VI of PP means in no uncertain terms that PP 0W-20 will be lighter than PU at all temp's.

 

[volk06]

Those specs arent apples to apples. The 0w20 specs are tested a lower temperature than the 5w20 specs.

 

[DragRace]

As long as you have a good battery,you will not have any issues with either oil during the coldest months of winter.

 

[Shannow]

Originally Posted By: CATERHAM
Yes but you forget that KV100 spec's do not correlate well with operational viscosity and say more about an oil's chemistry than everything else. Remember HTHSV trump's KV100. That in conjunction with the higher VI of PP means in no uncertain terms that PP 0W-20 will be lighter than PU at all temp's.


But the VI specs are calculated on the KV40 and KV100...

So how can you say that "operational" viscosity, which tends to remove the action of polymers with the high shear rates has any dependence or correlation to VI ?

 

[randomhero439]

Originally Posted By: Shannow
Originally Posted By: CATERHAM
Yes but you forget that KV100 spec's do not correlate well with operational viscosity and say more about an oil's chemistry than everything else. Remember HTHSV trump's KV100. That in conjunction with the higher VI of PP means in no uncertain terms that PP 0W-20 will be lighter than PU at all temp's.


But the VI specs are calculated on the KV40 and KV100...

So how can you say that "operational" viscosity, which tends to remove the action of polymers with the high shear rates has any dependence or correlation to VI ?

 

[CATERHAM]

Originally Posted By: Shannow
Originally Posted By: CATERHAM
Yes but you forget that KV100 spec's do not correlate well with operational viscosity and say more about an oil's chemistry than everything else. Remember HTHSV trump's KV100. That in conjunction with the higher VI of PP means in no uncertain terms that PP 0W-20 will be lighter than PU at all temp's.


But the VI specs are calculated on the KV40 and KV100...

So how can you say that "operational" viscosity, which tends to remove the action of polymers with the high shear rates has any dependence or correlation to VI ?

Because operational viscosity doesn't entirely "remove the action of polymers" but rather takes into account the effect of temporary shear that polymers are subject to.
But you do make a good point that VI is based on two kinematic measures that don't take this effect into consideration.
It would certainly be more precise if VI was based on HTHSV40 and HTHSV100 measurements instead. Nevertheless we do have to work with what we're given and VI is a calculation of viscosity change with temperature so lets not "throw the baby out with the bath water" as they say. If the VI difference between two oils was small and the oil with the lower VI was known to contain no polymer VIs one could presumably make a mitigating argument to minimize the effect of the VI difference.

Keep in mind this is all about predicting operational viscosity based on published PDS spec's which may or may not be all that accurate (as we have found out with some VOA reports). Nevertheless in my experience the most reliable predictor of operational viscosity at temp's down at least to 0C is first and foremost HTHS modified by the VI spec'.

 

[Shannow]

Originally Posted By: CATERHAM
VI is based on two kinematic measures that don't take this effect into consideration.
It would certainly be more precise if VI was based on HTHSV40 and HTHSV100 measurements instead. Nevertheless we do have to work with what we're given and VI is a calculation of viscosity change with temperature so lets not "throw the baby out with the bath water" as they say.


It was this question that had me come across the sub 20 grade SAE paper...

It had a few tantalising little gems in it, like base PAO KV100, HS150, and HS100, for a couple of oils, plus varying VII, so a pseudo VI for High shear could be worked out from the 100 to 150 figures, plus the viscosity loss at 100. Would have been great with a KV40 for the blend to go with it.

 

[CATERHAM]

Yes a KV40 measure would have made the 50 oil comparison much more interesting. Of the oils tested a HS150 2.6cP oil had nominally a HS100 viscosity of 5.6cP.

One thing I have learned in trying various high VI 20wt oils with the same nominal HTHSV of 2.6cP is that the higher the VI the lower the HS100 viscosity will be.

 

[Errtt]

Between the two (ultra & platinum), the ultra seems to be disappearing off the shelves.
If wanting to use ultra, might consider stocking up if you can find it. Otherwise, platinum seems to be a nice lube too.