This question will only be of interest to those who towing vehicle is fitted with an oil temperature gauge or have the ability to do so via an OBC (On Board Computer).
I've been meaning to post this since last year but for one reason or another it kept slipping my mind. Anyway, I regularly play around with my OBC during a journey and have noted that the oil temperature (even in high summer) hovers between the 80°C and 85°C mark. When collecting our Triton late last year and towed it home I noticed that the temperature was hovering around the 110°C mark most of the time and although it was nice and sunny it wasn't exactly baking hot. This of course was pulling an empty van of I'd guess 900kg with the dealer extras fitted so I'm wondering what sort of oil temperatures are going to be achieved pulling it closer to the 1200kg mark and at what point should one start being somewhat concerned. In fact, if any members have vehicle mechanics experience, what maximum temperature can one achieve and it still be considered safe?

I was towing a big trailer with a packing m/c onboard and the oil temp. was around 180.
I think it's the sort of thing you need accurate information on from the manufacturer.
I remember looking at a couple of Volvos and they both had oil coolers fitted.