Outer Limits 4x4 Board

the oil pressure recently has dropped a little. while driving (highway) it sits around 350-450 KPa, whilst under throttle, when off throttle can drop down to 150KPa (this is a bit low isn't it). only ever used to drop to about 250KPa. round town doesn't drop this low only after driving for more then 40mins or so.

engine is 4cylinder 3.9 diesel, turbo running round 13/14Psi, ruuning a litttle rich on fuel pump. never gets hot - pyro or eng. temp. under 'normal conditions'

i have no mechanical expertise, can anyone explain this to me, is there a potential issue?

cheers

when was its last oil change it had

plowy, bud i get the oil done every 5K, so regulary serviced.