Generally, the idling oil pressure of a cold car engine is 0.3 to 0.5Mpa, and the idling oil pressure of a hot car should less than 0.15MPa (for gasoline engine) and for diesel engine, the oil pressure runs between 600-1000kpa.
oil pressure sensor for range 15 psi, 30 psi, 50 psi, 100 psi, 150 psi.
Fuel pressure depends on the specific model, typical fuel pressure runs between 40-60 psi. In general, when driving the car, oil pressure should be maintained at 200kPa to 500kPa. When the engine temperature is high but low speed, oil pressure should not less than 200kpa; When the engine temperature is low and the speed is high, the oil pressure should not more than 500kpa.
The oil pressure is higher when the car is cold this is because two reasons :
1, the rotational speed is high when the car start in cold. 2, to lubricate the engine in the shortest time.