OK, defies logic. 45psi is 3 bar and that is well below the opening pressure of the PRV. Mine is on 4bar (5,000-5,200rpm) and changes ever so slightly with oil temp. I don't know what my relief pressure is, I have never revved the engine high enough with cold oil to see that pressure. One interesting fact with Rotax engines is that the running oil pressure actually increases with increasing oil temp. When I take off with 50deg C oil temp, the pressure is initially 3.6-3.7bar and then increases during climb to 4 bar when the oil temp reaches 80degC. This is a result of the diminishing suction line losses with decreasing viscosity, more than off-setting the increasing pressure loss in the post pump circuit.