I posted this on another thread in response to a troll, but it applies here so will post it here too:
I switched cars this week for a mpg test. I got on the freeway and set the cruise control to the mode of the traffic speed (the speed at which the highest percentage of the traffic is flowing) which is typically 80 mph and with my 36 mpg EPA highway rated 5 speed Corolla on my two way trip I got 39.5 mpg. The next day I did the same with the Impreza, also rated at 36 mpg highway EPA. I got 28 mpg. And I really tried, by switching to manual mode and allowing it to slow going up hills, to maximize the mpg.
I also noticed something else - my Corolla, in 5th gear (which is all it has) climbs hills better than my CVT in 5th (of 6) gear.