I don't see any problem with 1.5 bars at that engine temperature. It is all related to what viscosity oil he is running. I own two of these a 300TD and a 300D 184 and 163K miles respectively both 85s and that oil pressure seems OK to me at least running Mobil 1 0-40. I would definitely start to get nervous at 1.0 Bar....but that is just me.