An aggressive thermal management strategy (for each battery module individually) worsened the efficiency of the e-tron.
Audi e-tron is equipped with one of the largest battery pack (in terms of capacity) on the market, but the 95 kWh translated into a range of just 204 miles (328 km) (EPA). The WLTP rating is 417 km (259.1 miles).
The German SUV is classified on the bottom of the efficiency rank, with 455 Wh/mile of combined energy consumption (EPA), including charging losses.
We know that one of the biggest factors contributing to range that is lower than anticipated is available battery capacity of 83.6 kWh, which is 88% of the total value. 12% is an unavailable buffer to increase safety and long-term durability.
It doesn't explain however why the efficiency is significantly lower than in the case of competition, especially the Tesla Model X.
According to a Jalopnik article, some of the efficiency is sacrificed to run an aggressive thermal management strategy (for each module individually), which keeps battery temperature in optimum range. The narrow temperature window is probably great for cells, but it comes at an energy cost.
"Audi noted that the e-tron 55’s battery is built to handle serious abuse, and this is a key reason why range had to be sacrificed for the sake of preserving the pack’s long-term durability. This could be seen in the e-tron 55’s cooling system, which individually monitors and cools individual battery pack modules to keep them operating at optimum temperatures. These aggressive and redundant cooling systems ultimately add weight and consume power."
It might also explain why Audi e-tron is so consistent with charging at 150 kW in a wide state-of-charge window.
The question is whether we as consumers will be preferring models with higher efficiency/range, or those that nurse battery cells to the maximum? Taking into consideration Tesla Model S/X battery pack durability, maybe it was overkill by Audi?
Finally, there still might be other factors that limits e-tron efficiency, like the powertrain.