Another Oil Question

[HESS101]

Gentleman,
Again the 2003 manual says nothing about synthetic oils. Why? There are 10W40 0ils that are CI-4 already on the shelves. This all make me wonder how in the know or at least up to date GM is on the oils available. I'll keep reading. Two things I am becoming sold on are oils with protective properties of a 40W (for a diesel). But these newer oils that are thinner and flow more efficiently make sense also. 5W40 would be the ticket if it wasn't OD on polymers.
Could we set up a poll on oils that are being used?(administrator)? It would be interesting I think, now that college football is over.
What a subject! The life blood of our toys. I have learned alot but not sure of anything...yet.
Thanks again to all.
Steve

[LanduytG]

Hess101

Thank you, my point exactly. I am sure they are not up to date on oils. The Europeans are more advanced on the subject of oil than the US or at least they are attempting to move forward. I feel the US auto makers are helping the big oil companys take every dime we have.
The 10W-40 has been around for years and 30 weight oils are being used in diesels in euroepe. So why isn't the US that has all the technology doing it?
Not sure way they don't mention synthetic in the manual, after all the vet comes from the factory filled with synthetic.

Greg

[TraceF]

Like csimo I did not know there was a 10w40 CI product on the market. I think the presumption is correct that it is not recommended for DMax engines because GM doesn't know either.

Regardless, a CI 10w40 will be just as acceptable as a CI 5w40 or CI 15w40. The CI and the w40 is what is critical to the DMax diesel lubrication spec.

I can tell you this with certainty- the PCMO companies (PZL/QS, Valvoline, Castrol) do not even consider Amsoil a competitor. Their market share is probably less that a quarter of a percentage point. PZL/QS for example puts out in excess of 40 million gallons a year in total lubricants.

The FCI (fleet/commercial/industrial) guys, Shell, Mobol, Chevron, etc care even less about Amsoil. Or Amway!

[Kennedy]

Someone in Europe could maybe qualify this statement, but I would guess that the 30 weight oil is pretty much a necessary evil in an attempt to maintain strict Euro emissions certification...

[csimo]

I can't give an absolute answer as to why euro diesels use thinner oil, but I do know that many don't.

Possible reasons for thinner oil?

European diesel fuel is magnitudes better than our diesel fuel. This results in cleaner oil.

The passenger car diesel engines are not in the same class as our engines. They are light duty diesels designed to run like gasoline engines. They don't need the same kind of protection that a medium or heavy duty diesel engine needs.

In any case those engines are designed to run on the lighter oil... ours aren't.