Welcome aboard Tim.
16.5 sounds within the ball park when towing. There seems to be a fairly big variance with the CRDs - some manage to get amazingly good consumption, others tell horror stories.
We have a 2011 manual CRD and on our recent Central Oz trip towing a loaded camper and the Patrol full of 3 kids, food, recovery gear, spares etc we averaged 15.5-16.5l/100km doing 95km/hr. Obviously the harder your push the speed the higher the consumption. When doing 130km/hr (briefly) on the way to Alice it was closer to 20l/100km.
You should definitely fit a scanguage if you haven't done so already.
[edit]... damn, Nisshead got in just ahead of me!
