Hi all, Firstly, apologies if this subject has been discussed endlessly on here already...! I'm looking to do an engine & gearbox oil change on my 2014 961 Commando. I have the factory service manual which quotes the required spec as SAE 10W-40 API SG,SH & SJ, JASO MA. However, there is no mention whether this needs to be mineral based, semi-synthetic or fully synthetic. Is any type acceptable providing it is the correct viscosity & API spec? I already have Castrol 10W-40 grade API SJ but it is fully synthetic & would like to know if this is suitable to use or not. Does anybody know if the factory use a synthetic oil or a mineral based one? Many thanks.