I achieved 48.5 mpg on my commute to work this morning!!! My Focus is the Titanium model with the 18" sport wheel package.
Please note, this average was obtained over my 18 mile stretch of fairly flat highway. I reset the average just after the on ramp. I'm located in Houston, TX - The temperature yesterday 105f, and it was extremely humid this morning! Speed was kept between 55 - 62 mph. (60 mph speed limits = great gas mileage!)
Of course I can't achieve averages like this for an entire tank. (Yet...) My best tank of gas to date, just commuting back and forth to work, has been 35.3. :-)