I've collected a small amount of data using teslafi.com and noticed that efficiency tanks as the ambient temperature rises. TeslaFi.com Tesla Model S X Data Logger Temperature Efficiency Temperature Wh/Mile Efficiency % Miles Recorded 60 to 70 F 365.27 87.1 13.79 70 to 80 F 371.25 85.8 46.34 80 to 90 F 449.13 70.9 19.73 90 to 100 F 531.68 59.9 23.43 This data was recorded over one week of random urban/suburban trips of ten miles or less. Above 90 degrees, I get only 60% of EPA rated mileage. The cooler the weather, the better the efficiency. I presume this is due to the large amount of glass in the X, resulting in a lot of energy spent cooling. Can anyone else confirm? Is my A/C functioning at correct efficiency? Can we quantity the A/C load so that it can be factored into long trips?