To add to the above, being less viscous and thus thinner it seems likely that the thinner synthetic oil can pass through the oil pump and into the sump by gravity easier than could a thicker oil...? I suspect none of this was thought of as an issue in times when machines were built and used as tools and not toys that may not see regular usage..?
NOT that I am any different as my Morgan has evolved into being a garage queen.... Sigh..!
Thanks Luddite ! I gave my proposed 'cause' but forget to add the 'effect' doh
