While I'm no fan of the fuel ethanol boondoggle (or racket or whatever you want to call it), when used in engines designed for ethanol blended fuels, within the engine's designed range, there is no reason for ethanol blended gasoline consumption to increase more than about ([0.3]*[the ethanol fraction]) versus straight gasoline. E.g, for E10 (10% ethanol), fuel consumption should increase about 3%. Such a small delta is difficult to ascertain with statistical validity, and would typically require special test procedures and equipment [i.e. to get a statistically valid result].
"Schiefgehen will, was schiefgehen kann" - das Murphygesetz