Outer Limits 4x4 Board

I rented an 08 dually diesel and tow our van down to Rainbow and I was very suprised with the fuel consuption. I did 1044 kays and used 119 liters I was happy as, my old cruiser did a bout the same kays and I used not quite double. Are they all the good or is it only the new models. Is the 08 the old 3.2 or the new 2.5 couldn't tell as I don't know bitamissing that well.

08 is the 3.2

2.5 was introduced with the mn model with the big arse in late 09