Well, judging by the fueleconomy.gov numbers, the 2014 S85 uses 38kWh/100 miles and the 2017 S75 uses 34kWh/100 miles, ie, the 2017 S75 is 11% more efficient than the S85.
If the S75 is ~11% more efficient, 72.6kWh hours would be equivalent to ~81kWh in an S85, and remember, the S85 only has...