Eleven years ago, Tesla CEO Elon Musk revealed the Secret Tesla Motors Master Plan. In it, Musk laid out the vision for his upstart electric-car company: Build an electric sports car (the Tesla Roadster), use the profits “to build an affordable car” (which became Models S and X), and use that money to make “an even more affordable car.” Tonight, the first Tesla Model 3 sedans were delivered to owners at the company’s factory in Fremont, California. It’s the culmination of Tesla’s decade-long quest to build that more affordable electric car.

The company has taken more than 500,000 deposits for the Model 3, Musk said at a press conference early Friday, although he pleaded with reporters not to read too much into that number. ?We did everything we could to unsell the car,? he said, asking people not to extrapolate “demand from the reservation number.” Tesla built a handful of Model 3 cars in July, and Musk claimed production will slowly ramp up to 10,000 units per week by the end of 2018. That would be somewhere around 500,000 Model 3s per year, five times the number of Model S and X vehicles the company makes today and almost as many cars as Volvo sold in 2016.
Musk describes the Model 3 production ramp as an S curve: slow growth in the beginning, followed by a rapid rise and a plateau. As he has done in the past, Musk noted that vehicle production can move only as quickly as its slowest supplier can deliver parts. A...