Oil pressure indicator W124 / W201 – Engine worn or indicator spins?

Hello people, also at the risk that some members mekern……… a question about the oil pressure indicator: I would like to know what yours will indicate when the engine is running warm, best after highway ride. The following cases: W124 / E 200 Diesel / 255 tkm / Bj 1995 / oil pressure indicator falls now to 1.5 if warm/hot – Has he not made earlier W201 / 1.8 petrol / 175 tkm / Bj 1992 / oil pressure indicator falls only little off, almost never under 2.5 no matter how hot – Funny or How behaves How could the ad be disturbed? Can it be that the ad doesn’t work properly? Thanks and greeting Peetrock