Are the Ultra cold MRV and CCS rating real? when i compare them to other synthetics, they seem wayyyy better..Does that mean a 5w20 ultra can be used in lieu of a ow-20 oil for better winter protection? But how come the VI is low at 154?
Pennzoil Ultra cold ratings..
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Check again. The MRV and CCS tests are done with the oil at different temperatures, depending on the W rating.
http://www.widman.biz/English/Tables/J300.html
http://www.widman.biz/English/Tables/J300.html
PU would be a great choice for winter.
VI is the linear approximation of viscosity usually between 100c and 40c. The problems are that viscosity is not linear and 40c (116f) isn't exactly a 'cold' start. There are much better tests to estimate how a oil will flow in low temperatures.
VI is the linear approximation of viscosity usually between 100c and 40c. The problems are that viscosity is not linear and 40c (116f) isn't exactly a 'cold' start. There are much better tests to estimate how a oil will flow in low temperatures.
Originally Posted By: rikstaker
Are the Ultra cold MRV and CCS rating real? when i compare them to other synthetics, they seem wayyyy better..Does that mean a 5w20 ultra can be used in lieu of a ow-20 oil for better winter protection? But how come the VI is low at 154?
MRV and CCS spec's are extreme cold spec's which don't have much relevance even in a GTA climate.
In our climate an oil's viscosity index is what matters most in comparing 20wt oils and determining which will be lighter on start-up. Pennzoil Platinum 5W-20 (169 VI) will be about 20% lighter at 0C than PU, Mobil 1 0W-20 (173 VI) about 25% lighter and Toyota 0W-20 (216 VI) about 50% lighter.
Are the Ultra cold MRV and CCS rating real? when i compare them to other synthetics, they seem wayyyy better..Does that mean a 5w20 ultra can be used in lieu of a ow-20 oil for better winter protection? But how come the VI is low at 154?
MRV and CCS spec's are extreme cold spec's which don't have much relevance even in a GTA climate.
In our climate an oil's viscosity index is what matters most in comparing 20wt oils and determining which will be lighter on start-up. Pennzoil Platinum 5W-20 (169 VI) will be about 20% lighter at 0C than PU, Mobil 1 0W-20 (173 VI) about 25% lighter and Toyota 0W-20 (216 VI) about 50% lighter.
I think the OP has a valid question, for example...
5w20 grade Pennzoil MRV specs:
PP 11,100@-35 C
PU 7,750@-35 C
Pennzoil conventional 18,100@-35 C
The PP has the superior 169 VI vs 154 of PU vs 150 VI of Pennzoil conventional.
5w30 Pennzoil MRV:
PP 13,300@-35C
PU 9,000@-35C
Pennzoil conventional 25,400@-35C
Explain?
5w20 grade Pennzoil MRV specs:
PP 11,100@-35 C
PU 7,750@-35 C
Pennzoil conventional 18,100@-35 C
The PP has the superior 169 VI vs 154 of PU vs 150 VI of Pennzoil conventional.
5w30 Pennzoil MRV:
PP 13,300@-35C
PU 9,000@-35C
Pennzoil conventional 25,400@-35C
Explain?
Last edited:
Originally Posted By: LotI
I think the OP has a valid question, for example...
5w20 grade Pennzoil MRV specs:
PP 11,100@-35 C
PU 7,750@-35 C
Pennzoil conventional 18,100@-35 C
The PP has the superior 169 VI vs 154 of PU vs 150 VI of Pennzoil conventional.
5w30 Pennzoil MRV:
PP 13,300@-35C
PU 9,000@-35C
Pennzoil conventional 25,400@-35C
Explain?
thanks..you posed the question in a better way..
I think the OP has a valid question, for example...
5w20 grade Pennzoil MRV specs:
PP 11,100@-35 C
PU 7,750@-35 C
Pennzoil conventional 18,100@-35 C
The PP has the superior 169 VI vs 154 of PU vs 150 VI of Pennzoil conventional.
5w30 Pennzoil MRV:
PP 13,300@-35C
PU 9,000@-35C
Pennzoil conventional 25,400@-35C
Explain?
thanks..you posed the question in a better way..
CATERHAM basically gave the answer. The MRV specification is fine, if you live in a climate where it might come into play. As a general rule of thumb, VI is more representative of the oil's performance to more people.
To put it another way, if you're living in a place where you're going to run into temperatures corresponding to the MRV temperatures, then you're going to have some benefit choosing an oil from the 0w-xx or 5w-xx families, and from those families ones that have a good MRV value. If you're not, in such a climate, you'd be better served with a higher VI.
The viscosity curves won't be linear. You could compare the curves on Widman's calculator to give you an idea of things at more "normal" temperatures, but be aware that it won't provide anything useful at temperatures anywhere near MRV values.
Personally, I tend to choose a viscosity for the winter by SAE grade (i.e. a 5w30), with a quick check of spec sheets to ensure that the MRV isn't a marginal pass nor that the VI is approaching that of a straight grade. If you compare Mobil Super 1000 5w30 to Pennzoil Conventional 5w30, the former's VI is within one point of the latter's, but the Pennzoil conventional has significantly better MRV numbers. Or, you go to something like Petro-Canada, which whomps on both oils with respect to MRV numbers, and has a reasonable VI.
To put it another way, if you're living in a place where you're going to run into temperatures corresponding to the MRV temperatures, then you're going to have some benefit choosing an oil from the 0w-xx or 5w-xx families, and from those families ones that have a good MRV value. If you're not, in such a climate, you'd be better served with a higher VI.
The viscosity curves won't be linear. You could compare the curves on Widman's calculator to give you an idea of things at more "normal" temperatures, but be aware that it won't provide anything useful at temperatures anywhere near MRV values.
Personally, I tend to choose a viscosity for the winter by SAE grade (i.e. a 5w30), with a quick check of spec sheets to ensure that the MRV isn't a marginal pass nor that the VI is approaching that of a straight grade. If you compare Mobil Super 1000 5w30 to Pennzoil Conventional 5w30, the former's VI is within one point of the latter's, but the Pennzoil conventional has significantly better MRV numbers. Or, you go to something like Petro-Canada, which whomps on both oils with respect to MRV numbers, and has a reasonable VI.
Originally Posted By: Garak
The viscosity curves won't be linear. You could compare the curves on Widman's calculator to give you an idea of things at more "normal" temperatures,
I don't understand how it could flow better at -35C but not as well at 40C just because of the VI spec.
The viscosity curves won't be linear. You could compare the curves on Widman's calculator to give you an idea of things at more "normal" temperatures,
I don't understand how it could flow better at -35C but not as well at 40C just because of the VI spec.
It's not because of the VI specification - it's the other way around. The VI is a measure of the oil's viscosity properties. The formula uses KV40 and KV100 along with some values from some ASTM publication.
The best way to visualize it is to plug in a few oils into Widman's viscosity calculator. The way to really see the difference is to compare oils of the same SAE grade, but with very different properties. Take something like German Castrol 0w30 or a similar European 0w-30, and compare it to an SN/GF-5 0w30 like Petro-Canada 0w30 or Mobil 1 Advanced Fuel Economy 0w-30. Throw in something like Delvac Elite 222 0w30 in the mix for comparison's sake.
GC is a 0w-30, and is required to behave like a 0w-XX at MRV temperatures, and will flow better at those temperatures than a 5w30 or a 10w30. At operating temperatures, GC is thicker than most 5w30 and 10w30 varieties on the market, having a significantly higher HTHS than the SN/GF-5 varieties of 5w30 or 10w30.
That's an example of how the VI doesn't tell you a lot in the really cold weather (i.e. MRV ranges), notably because that number relies on KV100 and KV40. Viscosity graphs based on VI don't do a lot of good in such low temperatures, either. Similarly, the MRV won't tell you a whole lot about an oil's viscosity at operating temperatures. After all, a 50 grade could be a straight grade, a 0w50, 5w-50, or 20w50. And a 0w50 will be much thinner in the -35 range than will a 10w30, but it will be thicker than the 10w30 at operating temperatures.
I guess that's why we have VI and MRV - they measure viscosity behaviour at rather different temperatures (and ranges). They don't relate well to each other at all, except in extremely general terms. If something has such a low VI as to be a straight grade, well, MRV is pointless. But, there are 0w-xx oils that don't have spectacular VIs, either.
The best way to visualize it is to plug in a few oils into Widman's viscosity calculator. The way to really see the difference is to compare oils of the same SAE grade, but with very different properties. Take something like German Castrol 0w30 or a similar European 0w-30, and compare it to an SN/GF-5 0w30 like Petro-Canada 0w30 or Mobil 1 Advanced Fuel Economy 0w-30. Throw in something like Delvac Elite 222 0w30 in the mix for comparison's sake.
GC is a 0w-30, and is required to behave like a 0w-XX at MRV temperatures, and will flow better at those temperatures than a 5w30 or a 10w30. At operating temperatures, GC is thicker than most 5w30 and 10w30 varieties on the market, having a significantly higher HTHS than the SN/GF-5 varieties of 5w30 or 10w30.
That's an example of how the VI doesn't tell you a lot in the really cold weather (i.e. MRV ranges), notably because that number relies on KV100 and KV40. Viscosity graphs based on VI don't do a lot of good in such low temperatures, either. Similarly, the MRV won't tell you a whole lot about an oil's viscosity at operating temperatures. After all, a 50 grade could be a straight grade, a 0w50, 5w-50, or 20w50. And a 0w50 will be much thinner in the -35 range than will a 10w30, but it will be thicker than the 10w30 at operating temperatures.
I guess that's why we have VI and MRV - they measure viscosity behaviour at rather different temperatures (and ranges). They don't relate well to each other at all, except in extremely general terms. If something has such a low VI as to be a straight grade, well, MRV is pointless. But, there are 0w-xx oils that don't have spectacular VIs, either.
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