When I was in Europe last time, I had a van with double carburator and once I did 500 Km with it.  It could have been the last drop of gas but I was impressed.   And it was an air cooled van too.  So, for me to do less than 200 miles on a tank now on this sophisticated expensive setup, does not make a whole lot of sense.  But I have heard the science behind it and I believe it supposed to be better, only I have not gotten any of it yet in the last decade.
Zoltan