Mark,
Try describing your driving that yields 16-19 mpg.
I got 21 mpg for 40 miles in 25 degrees, short trips of 15 minutes or less in town. In the same 25 degrees, I got 32 mpg at interstate speeds.
In 80 degrees, 50-60 miles per hour, very little stop and go, I got 43 mpg today with a bit of a head wind. And, for the most part, I resist the 255 hp urge to floor it. Soft foot, try to keep the ECO on as much as possible, drive with load.
If you specify your routes, drive conditions, temps, and drive practices, there are some pretty experienced hybrid drivers around here who will generously give specific recommendations for better mpg.
Lewis