Just wanted to follow up on this:
I just got off the phone with Mobil 1.  The technician I spoke with said
that the 15w50 still had high levels of Zinc and Phosphorus, even with
the SM rating.  So unless anybody hear knows otherwise, I'm going to
assume it's okay...

-Wes

Wesley Pegden wrote:
> I know the SM discussion was just had recently.  However, reading
> through that discussion, it seems nobody mentioned this:
>
> The "reintroduced" 15w-50 Mobil 1 oil is SM rated.  It is not clear to
> me whether it has enough of the anti-wear additives, after reading lots
> of pages online of various tests of the oil.  Mobil-1's site has
> generally cryptic answers, which I don't generally trust.
>
> I know there is plenty of dino oil with 20w50 or equivalent with no SM
> rating and presumably the correct levels of Zinc, etc.  What about
> synthetics?  Are there equivalent synthetics with known good levels of
> additives?  (Castrol?)  Or does anyone have a good reason to think that
> the Mobil 1 is still a good choice?
>
>