From my experience with my 2 Aero S1's the needle tends to be around the 12 o'clock position once warmed up and doesn't deviate much from this even on hot days /traffic may not get past 5 minutes past 12 so sounds from your description your car may need looking at if needle climbing towards the red closer to 1pm?

sorry just realized you referred to oil pressure not water temp. Both my Aero's show really good high pressure but can't say at what temp /RPM.