I found the best way to keep the Mazdaspeed6 (AWD here too)from getting poor FE is letting my wife drive.
But seriously what she does is pretty much keep it out of full boost, our car will spool up quite quickly.. all speed6's were manuals, and she basically will grandmaw the car to speed, and shifting at low RPM.
Try that keep it from full spool and drive that Spec-b (great cars by the way) like a grand-maw, until you get to speed.