It depends on a couple factors, how fast I drive and if I use the heater or not. Using the heater causes the engine to turn on more often and run for longer since it uses a traditional heater core to heat the air to keep the cabin warm. If I drive 65-70mph I can get 39-40mpg pretty easily, if I'm going 80 or faster expect a decrease of a couple mpg. In stop and go or city driving I can get in the low 40s if I'm just driving normally. If I'm accelerating quickly, using the heater, and/or carrying my bike (trailer hitch), especially if I'm carrying the bike and travelling at freeway speeds, I will get around 35mpg.
Surprisingly enough, running the A/C doesn't really have much effect on fuel economy so I get the best fuel economy during the summer even if it is really hot out.
I cranked over the 20,000 mile mark a couple weeks ago and I'm about 2 weeks short of the one year mark for ownership.