The problem with the database, and the point I was trying to make, is that the only reliable results come from the same people driving both cars, not completely different sets of people driving the cars. So I used my own experience along with that of various publications, where usually the same people that drove one hybrid also drove the other, so I view their results as reliable.

My results are consistent, although they only reflect one style of driving of course. I remember one test in which I started the car when the engine was dead cold, and drove home, accelerating gently, coasting when I can, but mostly going on the highway at 79-80 miles per hour (I wanted it precise for comparison purposes).

The highway route was mostly uphill for 10 miles or so, and even though the hill is gentle most of the time, my HCH suffers: it got 33.3 mpg over the 16-mile route to my apartment. A Prius, driven the same way, engine cold, got 40.0 mpg. And the Prius was a rental so technically it might have done 41-42 mpg if I'd inflated the tires more.