Even during a year as wildly uncertain as 2020, Tesla Inc. managed to deliver just shy of its half-a-million-vehicle target. All things considered, it is a remarkable achievement and a leap over the roughly 367,500 electric vehicles delivered during 2019.

Delivering 180,570 of its Model S/X and Model 3/Y sedans over the three months ending in December, a 61.2% increase from the same period last...