I'll summarize for folks possible causes not often thought about:
- Tire pressure. Even 2 PSI can swing efficiency by 10%.
- Yo-yo'ing the car. Wife and I can drive back to back, but she isn't as steady on the accelerator. 5%-15% swing between us with everything else the same.
- Bluetooth connecting to the car. I've seen 3kwh avg. drop to ~2.7kwh from proximity unlocking and locking. 10% total difference.
- Initial cabin cooling and heating. 1-2kwh per trip at 72 degrees for 30+ minute drives.
- Acceleration. Pure -> Touring -> Grand Touring -> Grand Touring Performance -> Sapphire all have significant step up in power even in smooth mode. I imagine most people are accelerating quicker than they realize, myself included (complaints on a trip where family was following us to our destination in a RAV4).
- Smooth mode now provides roughly a .1kwh improvement when cruising above 55mph due to single motor usage for the GT, GT-P, and probably the Sapphire too.
- Highway Assist. .1-.2kwh efficiency drop vs manual driving for me. It is either the sensors, usage of Regen to stay perfectly at set speed, or more aggressive acceleration.
Hope this helps.
For reference, I sit at 3.11kwh lifetime on 21" with no aero covers and no wheel diffusers. This is loaded down with luggage, 2 adults, and 2 children mostly on road trips. It includes quite spirited drives in the mountains for several months of ownership.
