Glad you had a good trip to the small island. Wow 9.1 l/100km, that's great for a 2+ tonne truck.
I averaged about 11.1 on my D3 over 11,500kms on my Cape York trip. Normally it does between 10.8 to 10.9, but the car was fully loaded and there was a lot of off roading.
OT: here is a picture of it about to ford the Daintree River. BTW, I was croc aware....
And a pic of me doing the infamous Gunshot Creek crossing - the hard way.