[afterburn 549]

Things I think I know from several hours of study . (too many)
One-
Lake Jr. answered me with a form letter, with no answer. Just blah blah blah and he doesn't work for the piston ring place anymore.
The big thing here.
After reading everything I could find on the internet, (lots of tech stuff), one thing stands out from the Ford Mustang flat-plane crank crowd.
They were at one point having the same discussion about the two oils.
Now, the caveat is this, I don't know what their main and rod bearing clearance is so that needs to be considered.
These people take their engineering and engines as seriously as most of us do about what we own.
It was not a teenie-bopper discussion.
There was someone of authority and respected by others, like some of the posters we have on our board here.
The end of the matter, it was said- (he said)
"Don't use the Ero formula as the Amoil Signature is twice a good. "
They recommended 0-40 for their *applications.
That's a loose quote.

So compare that, with all the scientific jargon about Ero base stock, which I am pretty sure is a bunch of crap as Ero has no oil wells that I know of...!!!
The Ero oil thing, as stated, is based on LL (long life oil changes)
For me, I am staying with 5W 30 as this car will never see weather below freezing.
I will never use the 0-20 oils.
SOOooo that's the best answer I can tabulate.

PS- In all this from the Ford people, I gather there are some real problems with their *engines, hence the best oil for application discussion.