I'd like more details about the hybrid drive's parameters to see if I could get even better mileage. On my '08 limited, I always use the "econ" mode, and the cruise control most of the time.

For example, I have discovered that on level ground the car will leave the engine off until the throttle exceeds about 15 Kw. If the EV mode is on, you can go slightly above 20 Kw without having the engine start, but not for long because as soon as the speed reaches 25, the engine will start.

Above about 42 miles per hour, the engine is always turning, even if the fuel flow is zero and the energy display shows no engine output.

So, the information I'm looking for is stuff like exactly what conditions cause the engine to start or stop, and how does the computer decide when to allow the EV mode to become active.

I am using a ScanGauge II to get instantaneous RPM and fuel flow information.

On my first 20 fillups, I went 6109 miles, used 228.24 gallons, for an average of 26.77 MPG.

I hope this starts a general discussion of technical details and would appreciate any links to such information that others may have found.