Hi there mister technician.

You might go to this place and see what you are asking about.
https://oilguidepro.com/engine-oil-compatibility-chart/

After looking that over you might want to take the path of least resistance and trust the people at API or in EUROPE’s ACEA.

Feel lucky that you have an older engine that has had all those worries worked out and was only about viscosity.

With today’s engineering being presented, in the latest chain driven interference engines, that the oil is the least of their problems.

The whole labeling system is being revamped here and abroad I guess?
Just like car batteries you won’t know what you are using but it will have to have the right bar code for the computer or things in the car can go funky! Some real scamming is happening against the consumer.

So, just cross your fingers that there are doing their best to keep the engines running somewhere long past their warranty period.

Phil