Mobil 1 0W-30 Viscosity - Not what I would expect

[slalom44]

I looked up the viscosities of various oils on Mobil's website, and I'm surprised by what I found. I would have expected that Mobil 1 0W-30 would be thinner than 10W-30, with similar viscosity at 100C. Instead, I found this:
................. cST@40C ---- cST@100C
Mobil 1 10W30---- 62.0------ 10.0
Mobil 1 0W-30---- 63.1 ------ 11.0

If this is true, it just looks like the base oil has a slightly different viscosity, but 0W-30 is actually thicker at room temperature than 10W-30! I was assuming that their 0W-30 would be better than their 5w- or 10W-30, but now I'm not so sure.

Unfortunately, the website does not show the pour point for 0W-30 so I can't make any other assumptions.

Thoughts???

 

[kd5byb]

I seen the same in AMSOIL data - the 0W-20 is slightly thicker at 100 degC than their 5W-20 XL series oil.

But then again, you expect the two xW-30 and the two xW-20 oils to have a similar 100 degC viscosity and that is indeed the case.

later,
b
ps: excuse typos - typing w/one hand, holding two year old with other.

 

[kartracer55]

If this is the case then whats the point?

 

[MGregoir]

9.7 cSt and a 2.9 HT/HS on a 0W-30 would be just about perfect for most of the gas engines on the road in the US if they could make it.

 

[Pablo]

Don't think in terms of "thicker" or "thinner". Think in terms of formulating an oil to meet this specification:

http://www.infineum.com/information/api-viscosity-2004.html

And for sure forget about pour point. What are the Low Temperature (-35°C and -40°C and -25°C and -30°C) Cranking and Pumping viscosities of those oils?

 

[Audi Junkie]

Someone correct me if I'm wrong. It seems like good PAO base oil can sustain a higher HT/HS with lower +100c and lower visc. That is, this 0w-30 needs to be thick to make the needed for API spec 2.9cP, while another oil with better base, like Redline or GC, makes the HT/HS with a thinner oil. What is the VI of the Mobil 1 0w-30? Why would it need to be thicker than PP 5w-30 to make the same HT/HS?

 

[slalom44]

Thanks, Pablo. That makes more sense. If I understand this correctly, 0W- would be preferable at subzero temps, however it would not have any advantage at summer temps. Am I correct?

 

[Audi Junkie]

Not really. 0w test is at -30f, if that's what you mean by sub zero. I think the original post dramatizes the fact that 0w does not mean thin(ner) at warm, cool and cold temps. In this case it was compared to the cousin, M1 10w-30. Take that a step farther, compare to PP 5w-30 at +10f to -10f range, it's not thinner.

I think we can forget about the 0w-30 being the unthickened lil brother of the venerable Mobil 1 0w-40 A3, Euro Builder spec oil. It's just another "synthetic" oil that passes the cold-cranking test at FIVE DEGREES colder that the 5w-30 does.

If those five degree between -25f and -30f are important to the user in Anarctica, great. If you are buying it for long A5 change intervals, you aren't getting it and you might just be getting a bunch of bu11 over the mpg savings too, seing how it's not thinner at operating temps. On a par with RP's horsepower gain claims.

 

[Pablo]

Originally Posted By: slalom44
Thanks, Pablo. That makes more sense. If I understand this correctly, 0W- would be preferable at subzero temps, however it would not have any advantage at summer temps. Am I correct?


Yes and no. Yes the 0W would flow better at -0° temps. But insufficient information at higher temps. Maybe a tie or maybe the 0W-30 would do better....depends HT/HS and film strength AW additives.....

 

[Steve S]

What would be the difference as the engine "sees "it? How is the oil blended as far as base oil viscosities.

 

[Audi Junkie]

Originally Posted By: Pablo
Yes the 0W would flow better at -0° temps.


I thought we just determined it was thicker?

 

[buster]

Quote:
probably results from a mix of thinner base oils and/or the use of more alkylated naphthalenes. Adding friction modifiers usually results in lower HT/HS because it lowers traction coefficient as well.

 

[INDYMAC]

Does anyone know why companies use 40C and 100C viscosity tests for their data? These temperatures have nothing to do with cold engine starts or normal operating temps. What would be more useful for me is data on cold cranking ability, viscosity on a standard day (15C/58F), and then some temperature in the normal operating range of the engine (60-90C).

 

[dwendt44]

Old habit perhaps, INDY.
I would point out though that oil generally runs hotter than the coolant. So 212°F(100°C) seems reasonable.
32°F(0°C) would seem to make more sense for the cold end.
But that's just me.