Your post was moved to this thread because it is (like many before it) a post about "Why does my car use more miles than are on the screen"?
In short, miles will almost never roll off at 1:1 because the car does not store miles, it stores energy, and energy use is higher in the winter. You are also doing a bunch of things that use energy (leaving sentry mode on, pre conditioning etc).
The biggest mistake people make with these cars is something along the lines of "I only drive 25 miles a day, this car has 300 mile range, I should be able to charge once every 8-9 days and have plenty left over. It will never (ever) work like that.
There isnt anything wrong with your car. To minimize your energy usage:
1. Stop using sentry mode (will use 1-2 miles of range per hour, or somewhere around 20 miles every 24 hour period).
2. Ensure cabin overheat protection isnt on
3. Ensure standby summon isnt on
4. Only pre condition the car when its plugged into a circuit that can provide enough energy to cover the pre conditioning (a standard 15amp outlet doesnt provide enough to cover that in winter)
5. Come to grips with the fact that in winter the car will likely use approximately 20-30% more energgy than when its warmer
6. Dont expect miles to roll off 1:1 unless you drive like the epa tests which is the same as ICE vehicles.
