I call BS. Mobil 1 FS 0W-40 has a VI of 182 with KV40 of 78.3 cSt. Find me a 0w-40 that’s appreciably thinner at low temp. It’s got a lot of polymers, in fact. It’s basically the same viscosity as PP Euro 0W-40 and Castrol Edge PA 0W-40. All 3 are on the lower end of the 40 grade viscosity as well.
Keep using A3/B4 or?
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IBTL
THIS!!! Thank You!
Ultimately the conclusion of this thread seems to be that I will be well served to continue using A3/B4, "full strength", even if that means using 5W40 when that's what I can find at the local WM. I'll probably make more effort to hoard the 0W's when I can find them.
Fair to call BS, I'm just making a hypothesis on that based on the numbers I can find, which all point to it being thicker than the other 0W40's.
It’s not, you can see the numbers in the PDS for all of them. It’s one of the thinnest.
The dynamic viscosity curve drawn through the available data points, is appears closer to a 5w40 than competing 0w40 from what I am seeing. At least, that's what I am seeing, I could be doing it wrong or looking at different data... Sorry if that's the case maybe this is just a case of comparing different information? I was just doing some more research on this stuff and it looks like there was a big formulation change earlier this year and there are threads here on Bitog talking about it. It used to be one of the thinnest 0W40's by a long shot across the whole temperature range all the way down to having the lowest poor point of any A3/B4 I am aware of. That's no longer the case. Looks borderline 0W to me based on currently available information but formulations change all the time and what's on the shelf at the store could be one of several possible "versions" when it comes to just about any oil.
I care about the viscosity curve over temperature ranges more than the operating temp target for our application. Anything with a HTHS design emphasis (2.9 or 3.5 minimum target) is going to provide pretty good engine protection regardless of whether the measured viscosity at 100C is 9cSt or 18cSt and anywhere in there would work fine for a continuous long drive on the highway or running errand's all over town with any of our cars. The viscosity at 100C is the least of my concerns to be honest, which is why I happily use either 30 or 40 weight in these cars
My Wife drives 7 miles to work, I drive about 14. I go to lunch a couple days a week within a few miles of work, so maybe 3-7 mile round trip. Sometimes we just run down to the local pizza shop or convenience store or around the block to drop off something at a neighbors house, 1-4 mile trips. On most days, our cars are spending most of their time below that ~100C target operating temp at the oil. I suspect that MOST drivers if they took an honest tabulation of their driving, would find that their cars spend half or more of their time with the oil not at steady state operating temp, so the whole curve actually defines the "viscosity characteristic" of the oil, not just the viscosity at 100C.
Post your data then. KV40 and KV100. It’s very simple.
M1 0W40 (current):
Poor: -42C
KV40: 78.3cSt
KV100: 13.8cSt
Edge Euro 5w40:
Poor: -42C
KV40: 81cSt
KV100: 13.4cSt
These look similar and interchangeable to me.
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M1 0W40 (old)
Poor: -60C
KV40: 71cSt
KV100: 12.9cSt
Edge Euro 0W40:
Poor: -57C
KV40: 74cSt
KV100: 13.2cSt
These look similar and interchangeable to me.
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I'm of the opinion that the latest formulation of M1 0W40 isn't the "0W30" replacement everyone used to treat it like.
You must be trolling. You said it was thicker than competing 0w40s. It’s not in general, and if it is, it’s not by any meaningful margin. You also only give one example. Pour point is also completely meaningless. The higher pour point is because they are using Group III base stock not because it’s thinner or thicker.
I don't think you know what this means.
You keep referring to "pour" point which has been shown to you, is irrelevant. Are you planning to change your oil at -30C?
Actually nobody has shown me that it is irrelevant, they have just told me that it is.
I've read about how the test is conducted and wouldn't consider it meaningful if the results are fairly close, but we're talking about an ~18C spread here. It tells us there are meaningful differences in the formulations of these fluids. If 2 fluids are loosing their flow properties at the same temp and have similar viscosity at other temps then they have similarities. I'm not going to flush common sense down the drain here over this...
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I'm probably going to regret replying here but what you are seeing is the result of the use of PAO in the base oil blend. The only base oil that has consistent performance below 0C is PAO, because it has no wax in it, so there is nothing to crystalize, which is what causes base oils to gel.
PAO has advantages (excellent oxidation resistance, incredible cold temperature performance) and disadvantages (incredibly "dry", has basically no solubility, is hard on seals) and its disadvantages need to be dealt with by blending in other components, typically esters and/or AN's to increase solubility and offset the seal shrink tendency.
Ergo, you don't see PAO used often unless it absolutely has to be.
Group III, in order to achieve the 0W Winter grade, requires PPD's. PPD's drive down the temperature wax crystal formation happens at. You also tend to use very light Group III bases (like 4cSt) for this to be doable. This drives up Noack, which is capped at 10% for 229.5, which is why we've traditionally seen some amount of PAO in the Euro full-SAPS oils like M1 FS 0W-40.
Shell's GTL base oils allow the blending of 0W-xx oils with characteristics that haven't traditionally been possible without PAO. That is, a low enough Noack volatility and the ability to pass the CSS/MRV requirements. These base oils have less wax in them than traditional Group III (Yubase and similar) but are not wax-free. This means they need a lower PPD treat rate, but PPD's are still required.
Unlike PAO, a base oil with PPD's will hit a wall where the PPD's stop working. This artifact is observable in the Pour Point. Since PAO doesn't experience this phenomenon, you will see insanely low pour points, far lower than the temperatures that CCS and MRV are tested at.
HOWEVER
Just because a PAO base oil can pour at -72 or something, doesn't mean it will pass the CCS and MRV requirements for the 0W-xx designation. It still thickens as it cools, it just doesn't gel, continuing to get thicker and thicker. Almost exclusively, CCS, which has a much lower viscosity limit, will be what fails.
What this means is that you can have two oils, one blended with GTL that maybe has a pour point of -45C and another that's blended with PAO and it has a pour point of -63C and the GTL one may have a lower CCS viscosity, even though its pour point is massively lower.
Now THAT is a premium quality post deserving of a far better audience than I. (seriously, you guys are great, don't let me get you down).
If I'm understanding your post, which is very thorough and complicated (I'll try to keep up), it would seem to me that the old formulation of M1 0W40 (the 12.9cSt and -60C poor) was probably made with a PAO rich base stock, whereas the new formulation, is probably made with more "thin/clean" group III's, PPDs to suppress poor point and polymers to flatten the VI.
Given this difference in poor point caused by different base oils, would it be reasonable to assume that Castrol Edge 0W40 probably contains PAO (-57C poor), whereas the Edge 5W40, is probably formulated with more group III, PPD's, and polymers (-42C poor) like "new" M1 0W40? It would stand to reason that if Exxon is the only company with a "pure" enough group III to be formulated into a 0W-40, that Castrol would be hitting a 5W-40 with their best offering in this base oil category.
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I fully understand what you're saying about how an oil with a very low poor point might still have a higher viscosity than an oil with a higher poor point when compared at specific ultra-low temps above both poor points. The idea that some oils will suddenly go "wax" a few degrees below pumpability, where another will thicken up more gradually, actually does make perfect and reasonable sense given different oil formulations.
Based on what you're saying, if I had to pick a cold weather oil I think I would go with a PAO rich option, as it seems to me like it provides a greater margin of usability below its intended temperature range, and would perhaps be less susceptible to loosing that low temp capability as additives break down. Thoughts?
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They are all pumpable below any temperature you’ll be starting your car at. That’s how they get a 0W grade. Just buy Castrol Edge 0W-30 A3/B4 if you’re needlessly worried about M1 0W-40s not-so-poor pour point.
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The formulation of M1 0W-40 has changed many times over the years. It was first almost straight PAO as the base, then Mobil switched to blending in VISOM, which was their proprietary Group III+ base oil that behaved very much like Shell's GTL bases, then they went back to a more PAO-heavy blend with some Group III and then when Shell's GTL bases became available, they slowly started integrating those into their products, and that's where we are now. Just going by the SDS (which is NOT a recipe), it APPEARS that M1 FS 0W-40 is 30-40% PAO and 40-50% GTL Group III+:
HOWEVER, that SDS is from June 10th, 2022, though the German SDS from January, 2023, looks the same.
What is possibly taking place here is we are seeing the influence that swapping out ester for AN's in the base oil blend is having, if the concentration is high enough. AN's also have poor cold temperature performance. I'm somewhat hesitant to blame it all on this however, as HPL uses AN's in their oils and they have maintained low pour points, unless it's just a concentration thing, but that's purely speculation on my part.
Edge 5W-40 has no PAO, it's straight Group III:
While Edge 0W-40 has 25-50% PAO and 25-50% Group III (non-GTL) if we are trusting the SDS:
Interestingly, the SDS has the Pour Point for Edge 0W-40 as -45C, but, as I noted, the SDS is not a recipe, so I would generally lean toward the PDS over the SDS as to the accuracy of that figure.
CCS of mobil 1 FS 0s40 is unknown but the MRV@-40 is 30,500.
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If A3/B4 are hard to come by, why not have a look at a C3 oil? (I have heard you too have low sulphur fuel now, so lower TBN of a C3 should no longer be an issue).
C3 have HTHS of at least 3.5, just like A3/B4.
At least on our side of the pond, there are now far more 0w-30 and 5w-30 C3 than a3/b4 options.
If I were you, I'd try to get something like the american equivalent of Shell HU 0w30 AV-L (or one of it's sister brews). You seem to do a lot of short tripping, so you might benefit from the lower viscosity and very high VI, yet there is still a reasonably high HTHS to protect your bearings should you ever need to really work the engine.
C3 have HTHS of at least 3.5, just like A3/B4.
At least on our side of the pond, there are now far more 0w-30 and 5w-30 C3 than a3/b4 options.
If I were you, I'd try to get something like the american equivalent of Shell HU 0w30 AV-L (or one of it's sister brews). You seem to do a lot of short tripping, so you might benefit from the lower viscosity and very high VI, yet there is still a reasonably high HTHS to protect your bearings should you ever need to really work the engine.
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I am so glad I was on a trip last week 
Edge API SP dropped amount of PAO. It seems that most SP oils dropped PAO.
On other hand SP 5W40 oils bumped pour point in general below -40, mostly-42 to -45. Before, it wouldn’t be unusual to have 5W40 around-39.