In his last test of the Tesla Model X P90DL Optimus Prime before the sale and switch to a Model 3, Bjørn Nyland tested the battery degradation.
After around 100,000 km (62,000 miles) of the second battery pack (the first was replaced after 116,000 km (72,000 miles) under warranty, the overall capacity fade seems to be at around 8%.
Second battery pack 81.9 kWh (new):
- 35,000 km (21,800 miles): 79.3 kWh (down 3%)
- 75,000 km (46,600 miles): 77.2 kWh (down 6%) - 368 km (229 miles) of range assuming 210 Wh/km
- 100,000 km (62,000 miles): 75.1 kWh (down 8%) - 349 km (217 miles) of range assuming 210 Wh/km
More from Bjørn Nyland
The 8% drop is unusually high for a Tesla, but Bjørn Nyland explains that it's probably way above the average as the car was used to pull a trailer a lot as well as very often Supercharged (the available maximum charging power of the X is now restricted).
In the future, Bjørn Nyland plans to test Tesla Model 3 battery degradation too, which should be quite interesting, as those are Tesla's latest batteries with the newest battery cooling system.