the “best” 2 liters diesel?

Hello together, I myself drive a 2 liter pump nozzle 140 hp diesel and must say so far I have found nothing better. Sure, the new diesel are quieter, but consumption is very important to me and I come to 5.6 l in the long-term cut. I had some BMW rental cars (unfortunately no 120d) and am rel. disappointed, despite efficient dynamics and gentle driving the did not come under 6,x liters on 100km But also newer VAG diesel do not seem to be the pump nozzle consumption / performance Environment is of course also important (Euro6?). and pump nozzle is unfortunately bad, as far as NOX is concerned. As brand I find possibly still Volvo interesting. Who can give a profound assessment with regard to modern diesel ? power, consumption, environment ? or are all common rails anyway about the same now ?