I wish the author understood the reality of this as they consistently talk about 'altitude' throughout this article. Altitude is meaningless to an EV since it does not lose power or performance at any altitude since it does not depend on O2 for power (if I remember correctly, O2 levels decrease 3% for every 1000 ft gain in elevation above sea level). Further, due to reduced air density at elevation, the wind resistance is decreased and the efficiency (mile/kWhr of battery) would increase because there is less drag. Lastly, the drive from Boulder down the Front Range to I-70 is filled with hills so there had to be *some* consumption on the return trip.
Yes, there are some uphills on that route that's why It used 3% on the return trip instead of gaining charge.