I've never owned another car that left the rear camera on when you're driving either, but apparently Tesla does.
Again, I'm not positive as to what goes into the calibration, but there are differences in the wheel tire combo. I confirmed this with the SC yesterday and they didn't give specifics but did say there's ride height and sensor calibration during it.
Consider this, when you move from 20" wheels to 22" wheels, the following happens.
1) The front wheels get smaller by a VERY small amount that most cars would consider acceptable. This causes the fronts to do an additional 2 rotations on the 22" wheels compared to the 20" wheels over the course of a mile.
2) The rear wheels get larger by double the amount of the fronts but still VERY small amount that most cars would consider acceptable. This causes the rears to do 2 rotations less on the 20 wheels over the course of a mile.
Most other cars have a 1% tolerance, both of these fall within those tolerances. But, most other cars have slack in the driveline, and all drive wheels are ultimately connected in some shape or form mechanically. The Tesla has removed a lot of these complexities and controls via sensors and electronically, so it's not unfathomable that they are doing something for calibration to account for the two small variations in opposite directions. Especially when you consider Tesla's rather unique mandate for no wheelspin.
Is it something you'd notice day to day? Probably not. Could it have affects on giving different readings to the computer and sensors? Possibly. Maybe it reduces the amount of room before traction control kicks in. Or maybe the additional minor forward pitch in the car changes aerodynamics. Not sure, but I do know this car is a lot more particular than any other car I've owned.
