Quick update on oils:
API is the American specification whereas ACEA is the European specification
Just looked at owners manuals for 850's and C/V/S 70's of 1998.
Recommended oils are those meeting API SG/CD or SH - these are old standards of the day and were the highest performing of the time. Semi synthetics and all synthetics would generally meet this standard.
The owners manuals recommend
full synthetic oil for more arduous use - e.g. temperature extremes, towing and consistent hard driving.
As oils have improved, the standards have become more and more rigorous for things like temperature stability, viscosity stability, ash content, film breakdown, shear resistance etc.
Mobil 1 for example, is rated as API SN the most stringent current American standard and meets both ACEA A3/B3 and A3/B4. B3 is a high performance petrol engine standard and B4 is for direct injection diesels. Synthetics typically meet both.
Ideally you should be using an oil that meets ACEA A3/B3 or API SN. Mobil 1 10W/40 and Castrol Edge 0W/40 both do this. Both viscosity grades are suitable due to the wide range that full synthetic technology allows.
I've attached a link to a document which is all about oils that, if you have nothing better to do, is worth a read.
https://www.penriteoil.com.au/assets...ngine_Oils.pdf
Regards
John