The oil pressure meter
Reading the oil pressure well, that is quite handy. For most vehicles, after the cold start, the oil pressure gauge gauge needle is firmly in the corner where the stop is located. And when a nice piece has been driven, it is a lot lower when waiting in front of a traffic light. The oil pressure gauge thus immediately gives an indication of the oil temperature. Together, these things determine whether it should be taken a while to warm up the case or whether you can simply give a nice gas. The cooling water temperature meter is not the right guide for this. Because it only indicates the temperature of the cooling water and not the temperature of the block.
Also a matter of temperature
When you have Triumph three-cylinder we once noticed that it took even 40 kilometers before the block was really on temperature. That machine always got the 2500 kilometer of oil and was always carefully warmed up. The current owner now has the counter at almost 80.000 kilometers. And that's a lot for a machine that was always said to have an average of 20.000 kilometers between revisions / definitive engine damage.
The oil pressure
If the oil pressure after very hard work (a day in the Black Forest or Ardennes) is very low, then certainly for engines whose oil also lubricates the gearbox, it is high time to change the oil. For that oil change, it makes sense to no longer put a heavy load on the engine and to keep the pace touristy, or to insert an extra lunch stop to cool the engine.
If the oil pressure remains too low even after cooling / oil change, this may be an indication of deeper suffering. Do not immediately think of a complete overhaul, but first measure the oil pressure with a calibrated meter or have it done. You will not be the first to find that his nightmares about complete block revisions are based on nothing but a somewhat low oil level, on the replacement of the oil pressure gauge. Or the oil filter (Mercedes 230 E). Or the oil pump.