Not 100% about that, the moving parts shouldn't actually touch when moving, they are floating on a thin film of the pressurised oil.
Not saying you are wrong, just that I don't know.
What I do know is that actually pumping the oil around the engine takes a surprising amount of energy.
Last year, I changed the oil in the Series from 10/40 to 20/50, partly because of the very hot weather last year, but also because I got a good deal on the 20/50.
During a recent cold start on a bitterly cold day, I was surprised by how sluggish cranking speed has become.
I know it is the oil, because once the engine is up to temperature, it spins over at normal speed if you switch off and restart.
u saying that about the oil ive often wondered if an oil pre heater fitted on the TDV6 could possibly reduce the risk factor with shells and cranks issues ??
Plus talking of the series engines my old series 3 petrol safari never missed a beat and started on the button come rain or shine