That's the way it should be. The oil pressure gauge should peg when cruising. It's only at idle that it might drop to 15psi/1 bar and it usually has to be pretty darn hot out and/or after running it hard for that to happen.

The gauge is either marked as 0-15-30-45 psi or 0-1-2-3 bar which are roughly the same scale.

Sixto
95 S420
87 300SDL