I just completed about an 1100mi round trip from Atlanta - Melbourne (FL, about an hour east of Orlando). Loved the car, AWD non P, 19s, but efficiency didn't seem great.
Temps: drive down, started at 90F cooled down to about 80F towards the end of the drive after the sun set. Drive back to Atlanta started around 85 and cooled to 75 near arrival
AC: on auto, set to about 73
Weight: about 400# in pax and luggage on the way down, 250# on the way back
Winds: for the most part I think negligible. Checked the weather at some regional airports along the route and all were low (<5kts generally)
Elevation change: about -1k ft down +1k back
Speeds: between 70 and 80 most of the time, nearly all on AP. Occasionally a little slower and very occasionally up to 85 just to pass
Looking at how much charge I had remaining at supercharger stops, I averaged about 240-250 miles of range, which is about 300-310 wh/mi, and closely matches the counters.
I totally get that driving faster us going to eat up batter faster, but over prolonged periods of time, the best consumption I ever got going 80, was around 300. If I had just supercharged, this number was around 330. Slowing down to 70, I got only around 290 at best.
These numbers seem a lot worse than what others have posted. Am I wrong in thinking that?