Quick driving update - first full tank with snow tires, and winter diesel (not as efficient as the fair weather stuff) saw 9.1L per 100 kms, or 26mpg, mixed urban/suburban. About a third of this driving was spent in 4WD too, so this number will probably improve.
I have noticed, as has my wife, that it doesn't get up to operating temp. Slowly gets to maybe 1/3 max on the gauge so I'm wondering about the stat? New stat is now ordered, along with upper and lower rad hoses, and a new rad cap. ALL OEM Mitsu. We don't muck about when it comes to cooling. I'm wondering if the stat is either stuck open, or not even in place? I can pull the coolant temperature via the diagnostic port via evoscan, but haven't had a chance yet. I'd expect it should be 190-200 degrees when fully at OT?
This could improve fuel econ as well? Time will tell.