Please help me understand

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Originally Posted By: Quattro Pete
Originally Posted By: fdcg27
This is the reason that virtually any Grp III qualified for dexos 1.

While API SN oil could be group II, right?


...and a dexos oil can be a Grp II/III blend with an unknown proportion of Grp III, right?
The main problem with many inexpensive Grp IIs and dexos is that they crack the NOACK limit.
An oil formulated for 15% NOACK loss isn't going to meet dexos while it will meet API SN.
 
Originally Posted By: zeng
Is it alright to suggest Dexos 1 G2 combines API SN and ACEA A5B5 ?

It might be close, but I suspect we'll see a lot of dexos1 oils not claiming A5/B5. Have the Castrol synthetics brought A5/B5 back yet? I don't think Mobil 1 has, either.
 
Originally Posted By: Quattro Pete
Originally Posted By: Sierra048
What other factors make a 10w30 not Dexos adequate?

Probably cold flow properties and the fuel economy aspects that it affects.


That's why my first immediate thought was, as well.

It's not that they aren't any 10W-30 oils that "aren't good" -

it's just that they don't meet THAT EXACT spec.
 
Originally Posted By: Linctex
Originally Posted By: Quattro Pete
Originally Posted By: Sierra048
What other factors make a 10w30 not Dexos adequate?

Probably cold flow properties and the fuel economy aspects that it affects.


That's why my first immediate thought was, as well.

It's not that they aren't any 10W-30 oils that "aren't good" -

it's just that they don't meet THAT EXACT spec.


So this would this be the major factor as far as not meeting Dexos specs? As an example, squeezing out another 1/20th of a mile per gallon? I made that factor up, I don't really know. Would it have any affect on AFM system or any of the other computer monitored/controlled systems? Again, IDK. I'm just curious.
 
GM hasn't specified a 10w-30 for a long time. There's no reason for them to start, now. The grade is specifically excluded from dexos1 certification, as was shown in the thread already.
 
Originally Posted By: SilverFusion2010
It's a real shame. 10w-30 are great shear-stable oils


Yes and that's why I run them for summer oil every year.
 
Originally Posted By: fdcg27
Originally Posted By: Quattro Pete
fdcg27 said:
While dexos 1 was a step beyond API SN, it was only a small step.

Based on what I remember from Lubrizol performance charts, it was not a small step at all.

If you look at the numbers rather than a graphical depiction, the differences aren't all that great.
This is the reason that virtually any Grp III qualified for dexos 1.


Yes, you have to look at the numbers. The Lubrizol spider graphs/radar charts are NOT supposed to be comparable between standards. I.e., the graphic overlay is only valid when overlaying one API standard against another. They are not scaled to be accurate between, say, API vs. Dexos. There is a disclaimer to that effect somewhere on the page usually.

As to 10w-30, I'd be running it in any climate where I did not have to regularly start it in the single digits(F) or lower. Where I live, I run it year-round in all vehicles.
 
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Originally Posted By: JohnnyJohnson
Originally Posted By: SilverFusion2010
It's a real shame. 10w-30 are great shear-stable oils


Yes and that's why I run them for summer oil every year.

Yes good shear stability and low Noack volatility from 10W30, that Valvoline synthetic would be a nice oil. A little on the thick side too with KV100 = 10.8 cSt, which I like.

The whole Valvoline range show a TBN of 9.3 and a Sulphated Ash of 0.97 % which is bit more than I was expecting (in a good way). I'm use to seeing a TBN of 7 to 8 and a SA of about 0.8% with some of the older D1-G1 stuff. I'm not sure if this is just Valvoline being generous or if it's a D1-G2 requirement. Time will tell.

Same with the zinc at 830 ppm, I hope this is delivered, I've seen UOAs from other manufacturers that show as low as 600 ppm zinc, which doesn't seem like a full serve to me. Especially given the ILSAC limits make the full serve a diet portion anyway.
 
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