In fact DV4C is based on the older DV4 which is only second generation common-rail system with magnetic injectors that operates only with 1500 bars pressure. The lower displacement, no VTG turbo and no IC is another reason why this motor has so "bad" fuel consumption per KWh ... However I do think that even that at lower rpm below 2000 the real life consumption will be much better than if you are driving it with 2600. And that's because if you are with 2600 at 5th gear the speed will be well over 120 km/h and the aero penalties will be untolerable.
And look the newer generation of 3 litres diesel engines ....they only menaged the fuel consumption per KWh of a 15 year old TDI PD engine
