This is mostly correct observation with an incorrect conclusion. Oil pressures under load will be higher until oil temps come up. This is due to decreasing visc

This is mostly correct observation with an incorrect conclusion. Oil pressures under load will be higher until oil temps come up. This is due to decreasing viscosity that improves the fuel flow. It still remains though that slower moving pump moves less oil (the volume doesn't change with temperature, just how quickly it falls back to the pan) and less oil even with a higher pressure may not provide adequate lubrication. The other major issue that specifically effects cold idling is that the ECM is going to increase the amount of fuel dumped into each cylinder, past what gets completely burned. This leads to problem called 'quench' that leaves gasoline behind on the walls of the cylinder after combustion. This will mix with the oil on these areas and actually dissolve it over time. Anyways, don't take it just from me. No manufacturer specifies over 30 seconds of idle time for their vehicles: https://info.ornl.gov/sites/publications/files/Pub61263.pdf https://info.ornl.gov/sites/publications/files/Pub61263.pdf