But the company could face difficulties ahead. The increase in sales of the Model 3 could cause demand to soften in the fourth quarter.

The company, which until recently only sold tens of thousands of luxury cars a year, will need to find many more buyers for the Model 3, which sells for $46,000 to $64,000 before federal and state tax incentives. Mr. Musk said that the company expected sales to remain strong as it starts shipping the car to Europe in the first three months of next year and Asia after that.

Tesla produced more than 53,000 Model 3 cars from July to September, nearly twice as many as in the previous three months. Deliveries of the Model 3 totaled more than 56,000, about three times as many as in the previous quarter.

“As long as they keep producing more cars than the previous quarter, there’s a good chance they can keep profits going,” Mr. Whiston said.

In a sign that buyers are still interested in the car after months of waiting for it, Tesla said that of the 455,000 Model 3 reservations it reported having in August 2017, fewer than 20 percent had been canceled.

Tesla next year is supposed to start making a more affordable version of the Model 3 priced at $35,000, and Mr. Musk has said that Tesla would lose money on that model if the company produced it now. The cheaper Model 3 is important because the $7,500 federal tax credit available to buyers of Tesla cars will be cut by half on Jan. 1 and phased out entirely over the course of 2019, making the company’s cars more expensive.

Tesla recently began offering a Model 3 priced at $46,000 as an interim step before it can produce the $35,000 version. “We don’t really have the ability to get to $35,000 right away,” Mr. Musk said, but he said Tesla was “probably less than six months from that.”