Just go back from a trip with my SD. The trip was 800 km. I made it with one full tank and still shows 130 km to go... but average speed of the trip was only 100 km. I have done the same trip with average speed of 150 km and it took me 1 1/2 tank ..... what can i say... if drive the car very smoothly with out overtakes and kick downs.. the consumption is surprisingly good! i have managed around 5 to 6 lt per 100km..... but only up to 100 km of speed on flat highway... at least my SD (330hp) is consuming a lot from 150/160 km and above....