If I'm driving strictly highway, I can get 25.xx mpg going 75mph on my E9x M3. My combined average is 18.3mpg, strictly city driving (mainly redlights, not really heavy "traffic," but you can get a good cruising distance @ 45 mph between lights ). So, given a 33% increase, that hopefully will put me near 24.xx mpg on the S55 with my driving environment, which would be awesome. FWIW, I get a combined 25mpg on my 335i on the same loop, and with a stage II JB4 G5 ISO Board with the e-wastegates set to "0" (which keeps the gates open when cruising, mean zero boost), my instant MPG indicator read 36.xx mpg @ 75mph. I'm excited by this possibility when BMS gets their hands on the S55 and produce an algorithm for isolated boost control