I posted the same question, with about the same type mileage you are getting, about a few weeks ago. Check out the thread for some useful info.

The short answer (and good news) is that your mileage will improve as the engine breaks in. There are also small adjustments you can make in your driving style and to the way you maintain the vehicle to further help. My last tank (my fourth, so far) was more than 3 mpg better than my prior best, and so far I notice continued improvement as I start my fifth tank.

Don't give up on this technology or the HAH. It is fun to drive and with time will improve its FE.