I am enjoying the mileage benefits of my hybrid in addition to the real time efficiency displays on the dash in my 2 year old FFH currently with 25K miles.
I find myself occasionally becoming a hyper-miler; striving to attain ever better numbers with each tankful. I have gotten as much as 715 miles on a tank of gas, and my overall average MPG for the life of the car is 47.9.
I have recently encountered battery troubles insofar as after I turn the ignition off, the accessories (radio, dome lights) turn off within 30 seconds with the message that power is off to save battery power. Up to this time, I have been able to listen to the radio for at least 30 minutes without the ignition on.
I suspect that my 12V battery is in need of replacement.
I want to know if I will lose the accumulated MPG data if the 12V battery is disconnected to replace it.
I discussed this with the service manager at my dealership. He didn't seem even to understand what I was saying when I described my problem with no accessory reserve. He told me that my battery tested fine. (I suspect he may not have been all that familiar with hybrid systems)
I welcome any feedback as to this annoying problem with no power reserve, as well as the effect on data by disconnecting the battery, and any other relevant discussion regarding the low voltage battery, etc.