Back in the early 90's it was Castrol TXT 10W40. It was rated API SG/CD, CCMC European test sequences G4 / G5 (pre-dates ACEA), VW 500.00 / 505.00, Mercedes-Benz PD2, Porsche Approved (air & water cooled engines) and BMW Special Oils Approved.
It was a big step forward from GTX 20W50. The TXT 10W40 stayed cleaner looking for longer and didn't shear down and give bad gear changes in my shared sump motorcycle.
I used it until they stopped selling it.