Hi All,
I have literally been a T6 owner for 2 weeks and I have been thinking this very same question.
I had a 2003 T4 Cali for 8 years, loved the thing. However, it was our daily driver and with its age, kids, bikes and all the family duties, we needed something more practical and went for the Multivan. We forked out for a fancy 204 4motion Panamericana and I am gobsmacked by the difference in fuel economy!!
Its only early days so we havent driven it that much yet, and admittedly I have been experiencing the new power and refinement (although not excessively). That was until until i saw the mfd (low 20's). Since then I have been driving like a pensioner to see how much i can improve it.
I will run some experiments with my foot, the aircon, cruising function (which seems like BS to me), etc, to see what i can get from it.
But how is it that a new (relatively, 4yrs), supposedly efficient 2ltr diesel engine can be so much worse than the old 2.5ltr 5 cylinder from the T4 (that, being a Cali was also always loaded)?