pkincy

Correct the 5-30 is only for street driving.

Here is a statement from Tadge:

"As for the Mobil 1 0W40, it was not available when we validated these engines and, in its currently available formulation, it also contains more phosphorous and ash than we specify. So, even if we validated the 0W40 for track use, we would still have to recommend reverting to a DEXOS 5W30 for daily street use."

So I presume that this formulation now contains less "phosphorus and ash (sic)" so Tadge is happy. Does it meet Dexos 1 or Dexos 2? Somebody above said Dexos 2 but that is a spec for diesel engines. The European stuff I believe is Dexos 2 while the oil specifed in my Owners Manual (and likely yours) is a Dexos 1 spec. As I don't track my car and the 5-30 is available at $4.67/quart vs the title of the thread calling this stuff $20/Quart, I don't see any reason to change.

m3incorp

I had to smile at this one. Now, that is clever marketing. I would never suggest to anyone what they should or should not use. As someone that is somewhat inquisitive, I had to look at what the marketing was getting at. It made reference to "3 Ways". Number 1. Cold start protection. .....yep all 0W-40 offers better cold start protection vs a 5W-30. Number 2. Wear protection and specifically, reducing oil aeration. I had to research what the heck oil aeration is. Seems that yes it does help to reduce this oil aeration, BUT other items also have to be optimized such as the oil pump. Hmm did the oil pump and other items change?.... Number 3. Track to the street on 1 oil...thus meaning no need to change oils.; no denying that fact. Fine, if you aren't the type person that changes your oil anyway after hard track sessions. I guess the question is, why does everyone feel they must have the "new improved, only sourced from GM oil (expensive oil) IF you don't track your vehicle, IF your owner's manual states 5W-30, IF you typically don't put many miles on your vehicle and or tend to change vehicles before the warranty expires.

I am not trying to sway or upset anyone; just my own observations.........and note I didn't state what oil I use......and just because I wrote what I did, try not to assume . It was only an observation and a question.