
An oil pressure reading looks unambiguous, a number on a scale. What it means depends on what you measured with, where, and at what oil temperature. Workshop gauges smooth out exactly the short drops that hurt a bearing, and between the pump and the main bearings the pressure falls step by step.
Start with why standard oil pressure gauges cannot be trusted, then read about the measuring position. Why we do not promise flat bar figures, and what we measure with ourselves, is covered in the remaining articles on this topic.