The objective of this was, of course, to insure that all four ran out of oil at the same time?
Oh oh, one would certainly hope not.
The central oil tank (78 USGallons, as I recall) was used to refill (in flight) the individual engine's oil tanks (using two electric oil pumps).
On my longest flight in this type (17 hours) the oil required to refill all the oil tanks was an astounding...105 gallons
