I found an ancient post on the FP forum which said the oil for the Centaurus was AeroShell 100 U, apparently specially formulated for the engine.
One squadron or flight used OMD-270 instead in the Centauruses on their Beverleys in the middle east. Possibly because of high ambient temperatures?
Much to my surprise, it also said the TBO for the civil Centaurus was 3000 hours.