A normal oil gauge reading is between 25 PSI to 65 PSI.
The needle on the pressure gauge should settle at the midpoint after the car has been running for about 20 minutes.
If it settles toward the top of the gauge, it could be indicating high oil pressure.
The pressure relief valve could be stuck or faulty, or there could be a blockage in the oil delivery lines.
When your engine oil is cold the engine oil pressure will be higher but as your engine warms up and the oil warms up as well the oil pressure will drop some.
However it should not drop below 25 to 20 PSI or you may have a problem with the bearings or oil pump.
Although in some cases such as with older vehicles such as with my truck the pressure will be 60 PSI to 80 PSI when cold.
Then after the engine warms up the oil pressure will start dropping down to 15 PSI to 5 PSI and then settle on 2 PSI.
This has not been an issue and it has been doing this for a long time.
But normally the oil pressure should be higher than that.
Low oil pressure indicates insufficient lubrication is being provided to the motor.
A reading less than 20 PSI or under the normal range on the gauge is cause for immediate attention.
The problem could be as simple as a low oil level or a signal of serious engine problems.