Damn, 265F? Here in south Texas with 130 or so days over 100F I have never seen north of 250F before changing the oil thermostat to a FTP unit,and now I see maybe 230F at the highest when beating on it in traffic in the summer with the AC at full blast. The first pic is in traffic. The second screen shot I was beating on it pretty hard (see max boost)
Auto, MHD is set to Sport cooling mode.
operating temp Ideally you want your oil temp between 210-230. no more than 240-250 on hard driving. You dont want oil temps much lower than 200 degrees because you lose the ability to burn off fuel and condensation dilution.
Keep in mind that driving hard uphill (sea level to 3500ft elevation in 15min) places a lot of extra strain on cooling systems in general as airspeed is lower for a given output.
I was under the impression that you can run a modern hi-po synthetic oil at up to 300F before it starts breaking down, at the cost of reduced oil change intervals perhaps. Plus you can always go up a viscosity grade to compensate if need be... Here is an interesting link for you: