LDB

Not sure what you are referring to. MitchAlsap’s “higher” was referring to his numbers in the 60’s and 70’s, which are cSt, meaning centistokes, a direct measure of viscosity. So a higher number there means thicker and less flow. If you mean the 0 in 0W40, then yes, 0W40 is thinner with more flow at cold start than 5W30, but thicker at high temp. The confusion may be that Alsap was misinterpreting the data at 40 degrees C, which as pointed out in post #26 is 104 degrees F, not actually a cold start temp.

JoesC5

I had not noticed that. I checked some 0w40 European Formula Mobil1 that I purchased around 3 months ago and sure enough they had removed BMW off the label, but still have M-B listed(so I can continue to use it my Mercedes).

I still feel comfortable about using it in my C6 Z06 as I feel it is still probably a better oil than one made almost entirely with group III base stock. I still believe that the more group IV in the oil the better.

It makes me wonder what the hell is going on though. If a company is going to market an oil that is an "European Formula" oil for use in European cars, then why change it so it doesn't meet the European car companies requirements. Could it be that Mobil1 did not change their "European Formula" oil formulation, but that BMW changed their specs which is not now what the "European Formula" oil originally met several years ago.. Odd that it still meets VW and M-B if Mobil1 did in fact reduce the amount of group IV base stock from what it was before. GM pulled that stunt when they revised their requirements to dexos specs. The oil companies did not change their formulations as their oils met GM's requirements at the time, but GM changed their spec's of that the oil requirements so that the oil companies had to change their formulations in order to meet the new dexos spec.

Will be interesting to see if the new dexos 0w40 meets the VW, Porsche, BMW, M-B etc specs, or just GM's specs.

Gearhead Jim

To make it more confusing, it's possible that the new 0W-40 will meet the specs for the various European auto makers but won't be listed as such on the bottle. Sometimes doing any extra testing, paperwork, and producing containers with the updated markings, takes a while.

LDB

Lots of people seem to think that Euro oil is better than US oil, with more group 4 or 5 and less group 3 components. But where is the evidence? MSDS of Mobil1 German versus US oils are very similar. They typically have about 1/3 identified with buzzwords that are clearly group 3, another 1/3 with buzzwords that are clearly group 4, and the final 1/3 unidentified. Are we to believe the unidentified portions of Euro oil are group 4 while unidentified portions of US are group 3, and if so, why? In one sense, it doesn’t matter, as differences between group 3 and 4 are generally quite small. But in another sense, it just gives us another conspiracy theory to chew on, namely, why are Euro oils so much better than ours? The answer, of course, is that they aren’t.

The key question to me about the new Mobil1 0W40 is whether VI improvers needed to make it are now stable enough for 10,000 mile change intervals. No VI improvers on the planet were when I retired in 2010. Maybe they now are, which is why I’ll be looking very carefully at the info from GM and Exxon when it comes out in official print. And of course, since the oil companies don’t make the VI improvers, if the vendor-supplied VI improvers in Mobil1 are good enough to make reliable 0W40 for Mobil1, then it follows that most or all of the full synthetic 0W40’s will be similarly stable. We shall see.

MitchAlsup

I am using the numbers from Mobil One without any of the suffixing; it has an FS leading the 0W-40. It is not a racing oil, and all of the other numbers came from the same group.

MitchAlsup

The confusion is that mobile does not make the necessary data available.
The necessary data IS present for 5W-30 and 0W-30 but not for 0W-40.

LDB

If you want to get a pretty good estimate for viscosity at any temp, just draw a straight line through the two points they give you on semilog paper, the temp on the normal, linear axis and the viscosity on the log axis. Actual data will vary a little from that, but not much. You can download and print semilog paper from the internet. Three cycle works best, so the three cycles of log axis will cover 1-10, 10-100, and 100-1000 cSt.

rrsperry

Oops my bad...

vxplt

ErnieD

At the expense of beating this oil business to death, I did a few comparison/calculations on Mobil 1 5W-30, Mobil 1 conventional 0W-40, and what I think is the closest available oil to the new 0W-40 oil (U.K.'s Mobil 1 ESP Dexos 2 0W-40). Turns out that the U.K. oil has reduced phosphorus and sulfated ash specs (equivalent to the 5W-30 specs) and a corresponding reduction in TBN (that's apparently how they lowered sulfated ash). I ran some new viscosity numbers for all 3 oils at -5 degrees C (23 degrees F) figuring that would be about the lowest temps our cars would ever see at cold startup. The results: 5W-30 - 694.483 mm2/s (or cSt); conventional 0W-40 - 734.548 mm2/s; and ESP Dexos2 0W-40 - 764.160 mm2/s. The higher the number, the thicker the oil. So, at 23 degrees F, the thickest oil is the ESP Dexos2 0W-40 -- it finally gets as thin as the 5W-30 at approximately -30 degrees C (-22 degrees F) and then thinner yet at lower temps. Also note the HTHS specs -- the ESP Dexos2 0W-40 protects best at high temp/high shear conditions. I've attached the spec sheets for the 3 oils and here's a link to a Viscosity-Temperature Extrapolation calculator for you to play around with: http://www.viscopedia.com/calculator...extrapolation/

Ernie

Gearhead Jim

Years ago I got someone at Mobil to send me the viscosity-temperature graphs for 5W-30 and 0W-30. The two lines were perfectly identical all across the page, IIRC the range was +150'C down to -30'C. So I called them and asked about the lack of difference, they said the advantage of 0W didn't show up until below -30'C.
That seems to support your numbers for start temperatures.

MitchAlsup

Thanks,

What happened to the 5W-30 oil?

But in any event, 0W-30 oil is significantly thinner than 0W-40 oil at usefully cold temps.

Now, if the 0W-30 number is really a 5W-30 number, this simply shows that SAE uses a different number classification for W-40 oils than for W-30 oils.

ErnieD

Good eye -- the 0W-30 should read 5W-30.

Thanks.

AORoads

ErnieD nice work you've done. But I guess the only issue is, do you think there is enough real info from Mobil re the new oil to be able to make a good and fair comparison?

Besides being good for diesel and gas, and by your numbers better at high temps it seems the questions still remain: such as why switch; is it, and why is it better than the prior fill; has the 40-spread in number improved sufficiently; etc.?

ErnieD

From what I'm able to gather, the U.K. ESP Dexos2 0W-40 is not exactly the same as the new U.S. 0W-40, so we'll have to wait for specifics.

I think one of the key things for some folks is the ability to run the new oil on both the street and on the track -- should have somewhat better high temp protection.

AORoads

I wonder about the underlined. The prior recommendation was for a 15W-50. But, as you say, we may find out when the specs are printed.

buckeye4

Wow, I started this thread just to inform that dealerships have the new Mobil 1 0W-40 in stock and a chemistry lesson broke out.

Gearhead Jim

Have you been able to verify that the 0W-40 at your dealership is the new stuff that's factory fill for the MY 2019 cars?

Foosh

If it says Dexos, and 0w40 on the bottle, it's the right stuff.

AORoads

DuPont said it best maybe 50 years ago:

"Better things for better living through chemistry."

Oil is no longer stuff that gushes out of the ground, gets run through a paper coffee filter and poured into the crankcase (if it ever was that way ) Takes a lot of steps before that, especially that "synthetic" stuff.

Heck, I just found out thru this thread and one other that cos. like Lubrizol are the major suppliers of oil additives. And yet I've supposedly "known" the name of that company for a very long time. Big whoops! on me.