blunder anyway, because all I learned from my famous automotive electronics courses is that electronics control everything, including the exact amount of air ingested by the engine (compensated in T ° and pressure ) and the lambda probe checks if all of this is well burned and compares to pre-saved parameters
it is therefore advisable to inject after the measuring devices and to see what the lambda probe says: if it finds too much oxygen it induces a fuel over-injection
in fact, these systems are not really self-regulating feedback loops: the famous injection mapping, these are standard behaviors recorded
Still think about the warranty!
That said, for comparison I had an 806 2,1 Tdi (not Hdi) 110 CV in 1998
average mixed consumption 8,5, with the ladder on the roof. (mixed cycle, but little time actually spent in traffic)
a little more in winter because of cold starts
8,1 to 8,2 on vacation without bars or ladder, but with the air conditioning set to 23 °
the consumption of the 1,9 is good: it is in the standard of Mercedes C220, much lighter and less front surface.
I find that there is opposition between transparent roof and air conditioning: the more it is clear in the car, the more we need it.
Note for ultras: sorry a minivan without air conditioning is unlivable in summer: as soon as you open the windows at 80 km / H, there is an extremely unpleasant and tiring low frequency beat and as the glass surface is very large, there is very hot. The debate being whether we need such a big car, but that's another story ...