Sounds amazing, dunnit? Well it's true .. mostly.
It happened during a drive to the Point Reyes Lighthouse, which BTW is really cool but surprisingly distant from the South Bay. Part of the exercise was to discover what sort of mileage characteristics my new toy was capable of.
I'd been getting just under 40 MPG with it so far, mostly driving the 5 miles to and from work. It's kind of too bad that some of this time is spent in warm-up mode, which disables some of the hybrid functions.
So, how would it fare on a longer, mostly highway trip? I was surprised to be having trouble keeping it even at 45 MPG on the 880 freeway north. There was some stop/go traffic, perhaps from everyone else avoiding SF because of the Bay Bridge closing over Labor Day weekend. And there was a headwind. Sigh.
After leaving the lighthouse, I discovered why I'd been keeping the A/C on (as the owner's manual says, A/C affects mileage more on hybrids than other cars). Stupidly, I had managed to put the climate control in recirculate mode, which is great for A/C effectiveness but not for getting fresh air into the car. Being able to turn off the A/C, plus having a tailwind and being forced to stay below 40 MPH, kept it at or above 60 MPG for the entire 40 miles I was staring at the "empty" mark and sweating the search for a gas station.
This mileage continued through the rest of Mill Valley, up until US101 and the trip through SF and the 19th street path to I-280.
At speed, the story is only slightly worse. I tried setting the cruise control to 65 MPH (which, surprisingly, was about the speed of traffic on US101 from SFO on south), and I was a tad surprised to see the mileage hover between 53 MPG and 54 MPG.
All in all, very cool. Having this very interesting and rewarding system to oversee makes driving on the freeway a lot more interesting ... and I'm looking forward to taking another trip and being a bit more fastidious about taking lab notes. Driving to please the MPG meter is nothing new - Car&Driver's Pat Bedard wrote about this a few years back.