[MikeS100]

I spent a lot of time researching about the oil cooler before fitting it. I had decided not to bother as Volvo said it wasn't necessary but I took the caravan on a short test run as my first tow and the gearbox oil very quickly went up to 118 degrees in just a few miles (plug in scanner with real time data reading). I'm sure it would have gone higher if we hadn't reached the end of the tow by then.

So before going out again I changed the oil and fitted the cooler. It made a massive difference with even the steepest hills not going more than high 90's and very quickly dropping back down to normal (around 70 degrees if memory serves me correctly).

Changing down into 3rd in manual mode (4 speed auto) definitely makes a difference as well. For a short hill on the motorway I would leave it in D but on slower or winding A roads it's better in 3rd.