Well, it looks like 2012 is going to be a different year, eh.
2011 started with 44-47 mpg and was 54-56 in the summer.
I switched to non-ethanol and my worst tank so far for 2012 is 51.1 mpg for "winter blend" and sub 35 deg. F (1.6C) high temps.
It's a 1991 Geo driven at 5,000' elevation (1,524 M). Lowered, air dam, 3Tech 218/350 street/race cam, WAI, header, flow-through cat w/glasspack, moon disks, front studded 12" tires, Mobil1, vortex generators, sealed hood and slightly wider front fender (direct air around wheels),