Help me understand what makes one a Dexos oil and one not?

[Sierra048]

Just curious and would like for someone to help me understand what makes one of these oils a Dexos approved oil and the other unidentified grade oil not Dexos approved. I've read all of the information I could on BITOG and still don't understand. Are there other variables that are not listed. This info came from the PDS of each oil and both come from the same brand.

SAE Grade 5W-30 Dexos 1 approved
Specific Gravity @ 60°F 0.851
Density, lbs/gal @ 60°F 7.08
Color, ASTM D1500 3
Flash Point (COC), °C (°F) 220 (428)
Pour Point, °C (°F) -40 (-40)
Viscosity, Kinematic
cSt @ 40°C 64
cSt @ 100°C 11
Viscosity Index 165
Cold Cranking Viscosity, cP 5000 °C (-30)
High-Temp/High-Shear Viscosity, cP @ 150°C 3.2
Sulfated Ash, ASTM D874, wt % 0.9
Total Base Number (TBN), ASTM D2896 8.7
Phosphorus, wt % 0.077
Zinc, wt % 0.085


SAE Grade ?????
Specifc Gravity @ 60°F 0.852
Density, lbs/gal @ 60°F 7.1
Color, ASTM D1500 3
Flash Point (COC), °C (°F) 220 (450)
Pour Point, °C (°F) -39 (-38)
Viscosity, Kinematic
cSt @ 40°C 63.2
cSt @ 100°C 10.4
Viscosity Index 153
Cold Cranking Viscosity, cP 5000 °C (-25)
High Temp/High Shear Viscosity cP @ 150°C 3.1
Sulfated Ash, ASTM D874, wt % 0.96
Total Base Number (TBN), ASTM D2896 8
Phosphorus, wt % 0.077
Titanium, wt % 0.01
Zinc, wt % 0.085

 

[Bottom_Feeder]

Paying GM for the 'privilege' of putting it on the bottle.

 

[Jimzz]

If it meets SN rating and is 5w30, or 0w20 for some vehicles, then the only difference will come down to paying GM to have it tested and allowed to use the Dexos name on the bottle.

 

[paoester]

Dexos oil must pass more engine performance tests. Assurance of added performance compared to basic SN GF5 test suite.
One example of the many added tests on top of SN & GF5: dexos Turbocharger deposits test is tough to pass. Another: piston deposits less with dex.
I don't think GM gets much more than a penny or two per quart these days. Not like back in 2011 when it first came out when it was around a nickel a quart.

 

[ka9mnx]

The second oil looks like a 10w-30 which would not qualify for Dex1 Gen2.

 

[Quattro Pete]

Originally Posted by Sierra048
Are there other variables that are not listed.
There certainly are other variables, not listed in PDS.

In order to qualify for Dexos approval, on oil must comply with all the requirements listed here:
https://www.centerforqa.com/media/D1 Candidate Data Package rev20170910.xls

 

[Quattro Pete]

Originally Posted by ka9mnx
The second oil looks like a 10w-30 which would not qualify for Dex1 Gen2.

Yup, the CCV test gave it away.

 

[Mad_Hatter]

The difference between a GF5 lube and a Dexos 1 lube is the testing/requirements. Currently GF5 does not incorporate the tests necessary to certify a lube to D1G2 standards. ILSAC GF6 supposedly closes this gap by incorporating D1G2 tests and requirements. Plus, a Dexos lube MUST contain some synthetics to meet Dexos requirements, whereas an ILSAC GF5 doesn't (it can be 100% dino).

 

[Virtus_Probi]

Originally Posted by ka9mnx
The second oil looks like a 10w-30 which would not qualify for Dex1 Gen2.

Great eyes there!
You hit the nail on the head.

 

[2KBMW]

Originally Posted by paoester
Dexos oil must pass more engine performance tests. Assurance of added performance compared to basic SN GF5 test suite.
One example of the many added tests on top of SN & GF5: dexos Turbocharger deposits test is tough to pass. Another: piston deposits less with dex.
I don't think GM gets much more than a penny or two per quart these days. Not like back in 2011 when it first came out when it was around a nickel a quart.

Dexos1 Gen2 is far superior than regular SN.

 

[Sierra048]

Yes. The ungraded oil was a 10W30. It's the reason I started this thread. The info from the PDS for each oil seemed very close, if not the same, in their measurements. One was a Dexos oil, the 10W30 is not. My question: what makes the 10W30 not a Dexos oil? I'm not a tribologist and admittedly don't understand the chemistry of oil. In my feeble brain I would expect there to be tons of difference. Asked another way, why can't a 10W30 be a Dexos oil. I'm not trying to beat a dead horse to death here, I would really like to know. What damage or performance issues, if any, could using a 10W30 in a Dexos application cause? Thanks for your patience.

 

[Virtus_Probi]

Originally Posted by Sierra048
Yes. The ungraded oil was a 10W30. It's the reason I started this thread. The info from the PDS for each oil seemed very close, if not the same, in their measurements. One was a Dexos oil, the 10W30 is not. My question: what makes the 10W30 not a Dexos oil? I'm not a tribologist and admittedly don't understand the chemistry of oil. In my feeble brain I would expect there to be tons of difference. Asked another way, why can't a 10W30 be a Dexos oil. I'm not trying to beat a dead horse to death here, I would really like to know. What damage or performance issues, if any, could using a 10W30 in a Dexos application cause? Thanks for your patience.

The dexos1 Gen 2 spec and dexos1 before it are only for certain grades of oil...namely, 0W20, 5W30, 0W30 (with a lone example now in M1 AFE), and 5W30. That is how GM has chosen to define their spec, and I'd guess that GM recommends one of those grades in the vast majority of their US gasoline engines (I think the new Corvette might be an example of an exception in recommending dexos2?). I think that GM planned to recommend dexos2 for most gasoline engines in Europe, but I have seen dexos1 Gen 2 recommendations for some of their big sellers over there.

Running a 10W30 like the one posted above isn't likely to damage your engine and might meet the necessary performance requirements for dexos1 Gen 2 other than the cold starting stuff...it just CAN'T be dexos1 Gen 2, it's the wrong grade.

 

[Quattro Pete]

Originally Posted by Sierra048
Yes. The ungraded oil was a 10W30. It's the reason I started this thread. The info from the PDS for each oil seemed very close, if not the same, in their measurements. One was a Dexos oil, the 10W30 is not. My question: what makes the 10W30 not a Dexos oil?

For one, part of the Dexos requirement is the ability of the oil to deliver fuel economy savings. All 10W-XX oils are not considered resource conserving and are therefore automatically excluded from consideration.

 

[ka9mnx]

Originally Posted by Quattro Pete
All 10W-XX oils are not considered resource conserving and are therefore automatically excluded from consideration.

Actually, there are resource conserving 10w-30's but their fuel economy gain percent is quite lower than the other 30's.

 

[Sierra048]

Yes. I understand that a 10W30 won't be Dexos compliant vs a 5w30 or 5W20.

Quattro, thanks for the Admin contact info.

Just how much more fuel economy could one expect from a Dexos compliant oil in 5W30/5W20 vs a good synthetic 10W30?

I plan on running a synthetic 10W30 in my 2014 Sierra at my next OCI. I live in an area that never sees below freezing temps and it can get quite toasty in the late spring through early fall time frame. While fuel economy is important, I'm not going to panic losing a small percentage of that fuel economy due to a thicker at start-up motor oil. My intent in starting this thread was not to get everyone's seal of approval of my choice. I just wanted to broaden my understanding of just what makes an oil Dexos approved and how it stands up to something that might be just as good but doesn't have the Dexos approval. Your input has been valued and appreciated.

 

[buster]

GM has developed four new engine tests for this updated specification:

New General Motors Oxidation & Deposit Test (GMOD) verifies the improved oxidation and deposit control characteristics.
New Stochastic Pre-ignition Test verifies the added protection for turbocharged engines and pre-ignition concerns.
New Turbocharger Deposit Test verifies the added protection for turbocharged engines and minimizes deposit formation, which ensures optimal performance during engine life.
New Aeration Test (bubble control) ensures the air bubbles in the oil dissipate quickly to improve oil performance.
New Timing Chain wear (stretch) test.

 

[Mad_Hatter]

I believe ILSAC GF-6 due out in the Spring of next year will harmonize the two standards (D1G2 and GF-6)

As long as the lube you're planning on using has the API starburst along with the donut with the latest SN+ RC, I wouldn't loose sleep over it. (you probably waste more gas in a week just idling at stoplights)

 

[Virtus_Probi]

Originally Posted by Sierra048
Yes. I understand that a 10W30 won't be Dexos compliant vs a 5w30 or 5W20.
Quattro, thanks for the Admin contact info.
Just how much more fuel economy could one expect from a Dexos compliant oil in 5W30/5W20 vs a good synthetic 10W30?
I plan on running a synthetic 10W30 in my 2014 Sierra at my next OCI. I live in an area that never sees below freezing temps and it can get quite toasty in the late spring through early fall time frame. While fuel economy is important, I'm not going to panic losing a small percentage of that fuel economy due to a thicker at start-up motor oil. My intent in starting this thread was not to get everyone's seal of approval of my choice. I just wanted to broaden my understanding of just what makes an oil Dexos approved and how it stands up to something that might be just as good but doesn't have the Dexos approval. Your input has been valued and appreciated.

I would think 5W30 vs. 10W30 would be very similar for mileage in your environment as the viscosity difference at the temps you see should be minimal.
The chart at the bottom of this page seems to show that the viscosities are near overlapping at about 25C...it would be a lot better if the viscosity were shown on a log scale instead of linear, though.
https://www.kewengineering.co.uk/Auto_oils/oil_viscosity_explained.htm
10W30 and 5W30 are not distinguished by 40C and 100C viscosities, but by cold cranking and pumpability tests at -35C and -30C for 5W30 and -30C and -25C for 10W30. The test limits are similar for the two and the only really difference is an 8F change in the temps at which the tests are performed!
Running 5W20 over the other two is more likely to result in better gas mileage, but it might be hard to notice the difference....it is also quite possible to find a synth 10W30 that will be thinner than a comparable 5W30 at 40C and 100C and that could also result in slightly better gas mileage for the former.

I think 10W30 synth is a great choice in Georgia and I have run 10W30 in the summer up here in New England. I could probably get by with 10W30 year round if I didn't go to ski most weekends in the winter...don't want to push it when I am parking outside overnight in the Whites (actually running 0W30 again this coming winter).

 

[JohnnyJohnson]

Have you ever seen the red warning light come on in your GM oil monitor DANGER NOT D1G2?

 

[Rav4H2019]

Go with synthetic 10w30 or higher for summer in your gm. Dealer put in gm dexos5w30 whatever in a relatives 2016 equinox. Still timing chain failure at 36k miles.