5w-40 synthetic vs 15w-40 synthetic

[mbacfp]

The previous topic on finding a good diesel 15w-40 synthetic got me thinking. Why do they make a 15w-40 synthetic? In comparison to a 5w-40 synthetic (forget fuel savings advantages)...does the 15w-40 synthetic offer any advantages as compared to a 5w-40 synthetic?

Mobile Delvac 5w-40 Synthetic Amsoil 15w-40 synthetic
cSt @ 40ºC 98 103.2
cSt @ 100ºC 14.7 14.6
Viscosity Index, ASTM D 2270 156 146
Sulfated Ash, wt%, ASTM D 874 1.0 1.0
Total Base #, mg KOH/g, ASTM D 2896 10.1 10.4
Pour Point, ºC, ASTM D 97 -48 -40
Flash Point, ºC, ASTM D 92 249 238

Why would one run one or the other? Thanks.

 

[AirgunSavant]

Now I see Delo 400 at 15w30 just to throw that in the mix.

 

[BobFout]

Generally: Higher HTHS, lower NOACK, more shear resistant.

For your above comparison, compare Amsoil's CJ-4 5w40 to their CJ-4 15w40.

 

[BrocLuno]

Originally Posted By: AirgunSavant
Now I see Delo 400 at 15w30 just to throw that in the mix.


Likely most shear stable of all... Prolly a synthetic or iso-syn mono that happens to make the 15W pour point so it gets labeled as a multi because we all know you can't actually sell a mono to anyone now days

 

[AirgunSavant]

Thanks!!!

Originally Posted By: BrocLuno
Originally Posted By: AirgunSavant
Now I see Delo 400 at 15w30 just to throw that in the mix.


Likely most shear stable of all... Prolly a synthetic or iso-syn mono that happens to make the 15W pour point so it gets labeled as a multi because we all know you can't actually sell a mono to anyone now days

 

[zeng]

Originally Posted By: BrocLuno
Originally Posted By: AirgunSavant
Now I see Delo 400 at 15w30 just to throw that in the mix.
Likely most shear stable of all... Prolly a synthetic or iso-syn mono that happens to make the 15W pour point so it gets labeled as a multi because we all know you can't actually sell a mono to anyone now days

I would hazard a guess that this 15W30 in not VII-free though.

 

[userfriendly]

Delo 15w30 could be VII free.
Group III base oil is cheaper than VII, so the most economical way to blend 15w30
would be to add a synthetic base stock until the cold performance target is met.
A relatively low VI 15w40 synthetic blend would be another example of a VII free multi-grade.
A VII free synthetic could be labeled SAE 0w40, 5w40, 10w40, 15w40, 20w40, 25w40 or SAE40.
Delo SAE 10w could be labeled SAE 10w12.

 

[Bighorn2500]

Stick with the Mobil Delvac 1. Its good stuff and cheaper by the gallon then Amsoil.

 

[zeng]

Originally Posted By: mbacfp
The previous topic on finding a good diesel 15w-40 synthetic got me thinking. Why do they make a 15w-40 synthetic? In comparison to a 5w-40 synthetic (forget fuel savings advantages)...does the 15w-40 synthetic offer any advantages as compared to a 5w-40 synthetic?

Mobile Delvac 5w-40 Synthetic Amsoil 15w-40 synthetic
cSt @ 40ºC 98 103.2
cSt @ 100ºC 14.7 14.6
Viscosity Index, ASTM D 2270 156 146
Sulfated Ash, wt%, ASTM D 874 1.0 1.0
Total Base #, mg KOH/g, ASTM D 2896 10.1 10.4
Pour Point, ºC, ASTM D 97 -48 -40
Flash Point, ºC, ASTM D 92 249 238

Why would one run one or the other? Thanks.

This 15W40 is VII free.

 

[userfriendly]

It is interesting Zeng, that you post your "guess" is that Delo 15w30 is not VII free, but Amsoil 15W40 "is" VII free.
That sounds like bias reporting to me.

 

[Solarent]

Originally Posted By: userfriendly

A VII free synthetic could be labeled SAE 0w40, 5w40, 10w40, 15w40, 20w40, 25w40


I would challenge anyone to try make any of these multigrades VII free. I have never seen one. 0W40 is an especially difficult grade to formulate to and get all the visocometrics right.

 

[kschachn]

Originally Posted By: userfriendly
A VII free synthetic could be labeled SAE 0w40, 5w40, 10w40, 15w40, 20w40, 25w40 or SAE40.


You could label it anything you wanted I suppose but only one grade would be in compliance with J300.

 

[userfriendly]

My point is, there is likely a lot of label marketing going on, dancing around the SAE rules and guide-lines.
Some labels omit the "SAE" part which I suppose exempts the product from the SAE grading system.
The SAE 40 grade takes up a lot of room and should be split, or the rules modified for thinning and thickening out of grade.
SAE 0W40 can begin at 12.5 KV100C and slip a W grade in use, so depending on the price point of the product, is a VII free "SAE" 0w40 not possible?
The question should be, is the SAE grading system obsolete? All we ever hear and read about is HTHS these days.
The winter grade should be a temperature not a number.
SAE 0W40 would then be labeled -40/>3.5 which looks doable with a "classic VII" free "synthetic".

Of course, as previously mentioned, all changes to the grading and labeling system shall be done without the sales and marketing teams in the room.

 

[OVERKILL]

Originally Posted By: userfriendly
My point is, there is likely a lot of label marketing going on, dancing around the SAE rules and guide-lines.
Some labels omit the "SAE" part which I suppose exempts the product from the SAE grading system.
The SAE 40 grade takes up a lot of room and should be split, or the rules modified for thinning and thickening out of grade.
SAE 0W40 can begin at 12.5 KV100C and slip a W grade in use, so depending on the price point of the product, is a VII free "SAE" 0w40 not possible?
The question should be, is the SAE grading system obsolete? All we ever hear and read about is HTHS these days.
The winter grade should be a temperature not a number.
SAE 0W40 would then be labeled -40/>3.5 which looks doable with a "classic VII" free "synthetic".

Of course, as previously mentioned, all changes to the grading and labeling system shall be done without the sales and marketing teams in the room.


I'm not sure if you could blend a straight 0w-40 using PAO. You could do 5w-40 IMHO, but 0w-40 you might be running into issues due to the weight of the base necessary to get your "40".

I ran the numbers before using XOM's PAO bases and I believe that was the conclusion I came to at the time.

Spectrasyn 10 (10cSt) has a CCS of 8,840cP @ -30C, which is already above the limit for the 5w designation, despite MRV being well within the range for the 0w designation (36,650cP @ -40C) just as an example.

 

[userfriendly]

This is all good information.
I originally began my post at SAE 10w40 and higher, then went back and edited to include 0W40 and 5W40.
The reason is, the boutique oil companies are marketing these two light weight 40s with suspect formulations.
By the SAE splitting up HTHS for 10W40 and lighter from 15w40 and thicker, serves to fool the uninformed consumer into believing that all 40s are equal.
By the SAE allowing the winter grade to slip a grade in use, puts motorists at risk of engine damage in severe cold weather.

 

[Solarent]

Originally Posted By: userfriendly
My point is, there is likely a lot of label marketing going on, dancing around the SAE rules and guide-lines.
Some labels omit the "SAE" part which I suppose exempts the product from the SAE grading system.
The SAE 40 grade takes up a lot of room and should be split, or the rules modified for thinning and thickening out of grade.
SAE 0W40 can begin at 12.5 KV100C and slip a W grade in use, so depending on the price point of the product, is a VII free "SAE" 0w40 not possible?
The question should be, is the SAE grading system obsolete? All we ever hear and read about is HTHS these days.
The winter grade should be a temperature not a number.
SAE 0W40 would then be labeled -40/>3.5 which looks doable with a "classic VII" free "synthetic".

Of course, as previously mentioned, all changes to the grading and labeling system shall be done without the sales and marketing teams in the room.


I think you might be misunderstanding how the J300 works. In order to claim 0W40 you have to meet the high temperature requirements for 12.5 KV100C, but you also need to meet the CCS and MRV requirements for the cold temperature requirements (which is how you get the 0WXX half of the grade). By the guidelines you are required to label your product at the lowest possible "W" in combination with the correct high temperature viscosity. You have to have both parts to claim the complete grade. Otherwise you just have a monograde SAE 40 which is what you get in your hypothetical "VII Free Synthetic".

I don't think the grading system is obsolete. I think that alot of people don't really understand what it means because of all the folklore around "a multigrade oil that is a 40 weight that acts like a 0 weight in the winter." This isn't how the J300 really works and perpetuating that just adds to the confusion.

As far as I know, 0W40 HDDEO (which there are only 2 registered with the API) are VERY complex formulas and both require advanced base oils (PAO and/or Group III+) and advanced VII's (not your run of the mill OCP). If someone comes up with another way to do it I would love to hear about it.

 

[kschachn]

Originally Posted By: userfriendly
This is all good information.
I originally began my post at SAE 10w40 and higher, then went back and edited to include 0W40 and 5W40.
The reason is, the boutique oil companies are marketing these two light weight 40s with suspect formulations.
By the SAE splitting up HTHS for 10W40 and lighter from 15w40 and thicker, serves to fool the uninformed consumer into believing that all 40s are equal.
By the SAE allowing the winter grade to slip a grade in use, puts motorists at risk of engine damage in severe cold weather.


Slips to what? -10W?

 

[userfriendly]

The three 0W40 I have used are;
Esso XD-3 from the late 1990s to early 2000s before the merge with Mobil.
Mobil 1 from 2005-2010 and Duron ever since they rolled out 0W40 at half the price as the others.
The Esso XD-3 had no API certifications, and I think Duron is still that way.
Why license for a grade with few if any OEM approvals?
"Suitable for use" I believe depending who said it.
Obviously I trust Esso and Petro-Canada, the small players, not so much.

 

[OVERKILL]

Originally Posted By: userfriendly

Esso XD-3 from the late 1990s to early 2000s before the merge with Mobil.



Are you talking about the merger of Exxon and Mobil? Because that happened in the late 90's. Imperial Oil/Esso are a Standard Oil original, just like Mobil, Exxon and many others. Hence Esso being literally SO (Standard Oil). The ExxonMobil company owns a majority share (just under 70%) of Imperial Oil but prior to the merger, Imperial was an Exxon brand.

 

[OVERKILL]

Originally Posted By: userfriendly

By the SAE allowing the winter grade to slip a grade in use, puts motorists at risk of engine damage in severe cold weather.


A 0w-40 turning into a 5w-40 really isn't a huge issue in most of the world though

And they are ALLOWED to slip, I don't think I've ever seen anybody run a CCS and MRV test on used oil to see if they actually did. And this isn't exclusive to just this grade, it is allowed for any of them.