0w-20 Synthetic Comparison Datasheet

Status
Not open for further replies.
Joined
Jun 6, 2017
Messages
190
Location
FL, USA
Hey guys, I am trying to come up with a 0w-20 datasheet to compare basic specs for a few different manufacturers.

Been working on this for a little while scouring the internet and OEM websites but I cannot find some info, ie: TBNs, NOACKS, HTHS.

Maybe you can help me out if you know any of this data.

 
Don't forget to add VSP on there. Not the most impressive spec but, the best Ive used in our Subaru. Even against M1 EP purportedly real synthetic.
 
My table is coming together nice but I still need some more data. Royal Purple has really been a let down. First, I think the 177 VI for RP is bogus because the V for 40*C and 100*C is on the lower end. Second, they don't even have a basic spec for pour point which all other manufactures include.

Check it out. Seems the leaders are Redline, Amsoil, and M1 EP. Seems M1 is the best for the money.

 
Last edited:
- How could the VI be bogus? It is what it is based on the two viscosities.

- How are you judging viscosity at 40C? I would think a lower viscosity at 40C (ie. closer to the operating viscosity) would be preferable, but you have graded it oppositely. What is the benefit of a higher viscosity at low temperature?

- Pour point is not a standard for engine oils. So it provides little to no usable information. Low temperature cranking viscosity (CCS) and low temperature pumping viscosity (MRV) are important and provide relevant viscosity data with regard to engine performance. Though they don't appear to provide those either.
 
You are right, 177 is not bogus, I mistakenly thought the greater the difference between 100* and 40* C, the oil would have a greater VI, this is the opposite.

While we are talking about a very small margin here and a very light grade of oil, I was under the impression that a greater viscosity at 40*C (104*F close to my starting temp in the FL summer) would provide more protection. Looking at the HTHS numbers would confirm this. I understand oil loses viscosity over time as well.

Pour point is a property of the oil. I would use it to compare how an oil flows in cold temperatures. The lower the pour point the easier an oil will flow in cold temperatures.
 
Last edited:
Originally Posted By: shurguywutt
... While we are talking about a very small margin here and a very light grade of oil, I was under the impression that a greater viscosity at 40*C (104*F close to my starting temp in the FL summer) would provide more protection. Looking at the HTHS numbers would confirm this. ...
Uh ... not exactly! Better recheck your logic! If "greater viscosity at 40°C ... would provide more protection," then lower viscosity would provide less. Viscosity of any of the oils at 100°C is far lower than any at 40°. Yet, somehow, engines survive at that higher temperature. How do you figure that's possible?
 
It is possible for an engine to survive at a higher temperature because that is what they are designed to do. That is why engines have a cooling system and an oil system.

I am comparing data sets here. Obviously the viscosity of any oil at 100°C is far lower than any at 40°, that is physics. I was only making a comparison of the viscosity of the oils at 40*.

Everything that I have read has the HTHS number going up as viscosity increases. So logic says a more viscous oil would protect against higher temps and stress. But I could be wrong.
 
Last edited:
Originally Posted By: shurguywutt
... Everything that I have read has the HTHS number going up as viscosity increases. So logic says a more viscous oil would protect against higher temps and stress. But I could be wrong.
The HTHS "number" IS viscosity at a specified high temperature (and shear rate), so yes, higher viscosity in those conditions protects better against high loading. That doesn't explain why you feel there's any advantage in maximizing viscosity when the oil is only lukewarm. It's certain to be much higher then than the engine needs; otherwise the engine couldn't survive at normal operating temperature.
 
Originally Posted By: CR94
Originally Posted By: shurguywutt
... Everything that I have read has the HTHS number going up as viscosity increases. So logic says a more viscous oil would protect against higher temps and stress. But I could be wrong.
The HTHS "number" IS viscosity at a specified high temperature (and shear rate), so yes, higher viscosity in those conditions protects better against high loading. That doesn't explain why you feel there's any advantage in maximizing viscosity when the oil is only lukewarm. It's certain to be much higher then than the engine needs; otherwise the engine couldn't survive at normal operating temperature.


Wouldn't higher viscosity always protect better as long as the flow is sufficient to be pumped to all parts of the engine in this case? (which is should because all are 0w-20 grade).

A higher HTHS viscosity would protect better in an extreme engine condition. Logic would tell that a "slightly higher" viscosity at 104* would protect better than a lower viscosity at the same temp.
 
Even the lowest of the viscosities at 104°F is still 5 times higher than the viscosities at operating temp and it doesn't say anything about shear thinning like HTHS does. Kinematic viscosity doesn't protect against anything.

Flow isn't an issue at 104°F, but it becomes an issue when you get to temps below the winter rating (-40°F for a 0w)
 
Originally Posted By: shurguywutt
You are right, 177 is not bogus, I mistakenly thought the greater the difference between 100* and 40* C, the oil would have a greater VI, this is the opposite.



NO, you were correct the greater the difference (KV40 minus KV100) will result in a higher VI (=Better).

For economy during warmup you want the KV40 to be as close to operating viscosity as good oil chemistry allows at a given price point.

High-ish startup viscosity (well above operating viscosity) will provide no engine wear improvement durig warmup.
 
Last edited:
Originally Posted By: ARCOgraphite
Originally Posted By: shurguywutt
You are right, 177 is not bogus, I mistakenly thought the greater the difference between 100* and 40* C, the oil would have a greater VI, this is the opposite.



NO, you were correct the greater the difference (KV40 minus KV100) will result in a higher VI (=Better).


confused.gif


That's not right.

The more stable (less change) the viscosity is over a temperature range, the higher the viscosity index will be. The only exception to that I've ever seen is at very low viscosity (4 cSt and below at 100C) where the VI calculation starts to get a little loose with the numbers.
 
That's right, you are Correcto Mundo, MotoT

Brain on drugs Yesterday. I heard it the wrong way and answered the wrong way.

Wonder if and oil would hrut a cold started motor if the MRV viscosity was 100cP at -40 and the vi was unimaginably high.

Lets say Kv40 = 10cSt, KV100= 9.7cSt

would the engine be insanely noisy during warmup?

The oil Hot oil in a Ice cold motor postulation ....
 
Viscosity at 40°C is pretty much meaningless on its own for an engine oil; it is essentially there only to allow the calculation of the VI (and thence interpolation and extrapolation to any other temperature, within reason).

Another thing you haven't considered in your grading is the statistical reproducibility of test methods. I believe that the reproducibility of the HTHS test is 3.9%, meaning in essence that any result that is within 3.9% of another result can not be considered to be different (in other words, if you retested the oil with the 2.58 cP result in another lab, you could get a result of 2.68 cP and it would still be "the same"). So you can't say 2.58 is 'bad/red' and 2.6 is 'OK/green' - they are the same. The same principle applies to all of the test methods, each with their own reproducibility criteria.
 
Originally Posted By: ARCOgraphite
Lets say Kv40 = 10cSt, KV100= 9.7cSt

would the engine be insanely noisy during warmup?

The oil Hot oil in a Ice cold motor postulation ....


Given that you would have the MOFT of normal temperature running, and the AW additives outside their range, I would think that's a recipe for disaster.

for example take the Sequence IV testing...oil is "warm"ish viscosity is heading along it's exponential to operating viscosity but the AW package isn't functional as yet...perfect storm for camshaft wear.

As bobbydavro has stated...lower or higher temperature is less wear (lower temp, more hydrodynamic, higher temperature more AW influence)
 
Last edited:
Originally Posted By: weasley
Viscosity at 40°C is pretty much meaningless on its own for an engine oil; it is essentially there only to allow the calculation of the VI (and thence interpolation and extrapolation to any other temperature, within reason).

Another thing you haven't considered in your grading is the statistical reproducibility of test methods. I believe that the reproducibility of the HTHS test is 3.9%, meaning in essence that any result that is within 3.9% of another result can not be considered to be different (in other words, if you retested the oil with the 2.58 cP result in another lab, you could get a result of 2.68 cP and it would still be "the same"). So you can't say 2.58 is 'bad/red' and 2.6 is 'OK/green' - they are the same. The same principle applies to all of the test methods, each with their own reproducibility criteria.


Wouldn't one assume oil companies would list their "best" values on their data sheets to begin with?
 
lots of variables or sure! oils tested are newly blended + some specs are easily "propped up" with short live cheap additives!! we are being told group III "synthetics" rival PAO, but for how long!!! also from reading the quality of viscosity improvers vary. oil manufacturers + blenders are very tight lipped about base oils, but oils like Redline that cost more but should last longer + protect better with their superior Ester base oils. others Amsoil included prolly only use enough better base oils to meet a spec. i use some mobil I 10-30 extended performance + i understand they use some PAO in the blend. Motorcycle oils are nuts with their prices being double the other group III synthetics. can the additives used be that much more $$$
 
although not up to date motoroilevaluators.com list a lot of oils + specs + they note no spec= the poorest spec!!! yes they are hiding something, like the few oil blenders that tell you PAO or Ester, they are few + want to justify their price, others just say nothing + tell nothing even todays amsoil!!!
 
Status
Not open for further replies.
Back
Top