[Jim314]

So BG Universal Synthetic ATF is described as meeting or exceeding the requirements of AW-1. But what is the source of authentic AW-1?

One supposes that each auto manufacturer might have a different source for the factory fill of fluid for the 6-spd Aisin tranny. Aisin might make recommendations or consult, but each manufacturer might have its own cost/benefit analysis and make its own choice. I don't have any idea; just speculating.

Each major auto mfgr might deal with the lubrication suppliers and decide whether the supplier has an existing product which it could use or they might request a special formulation. Once again, I'm just speculating.

Anybody know what the practices actually are?

I wish the auto manufacturers wouldn't keep this so secret, but I guess that is the nature of the business.