UNITED STATES.- Tesla Inc. made 5,031 lower- priced Model 3 electric cars during the last week of June, surpassing its often missed goal of 5,000 per week. But the company still only managed to crank out an average of 2,198 per week for the quarter.

Tesla reported making 28,578 Model 3s from April through June, according to its quarterly production release on Monday.

The Model 3, which starts at $35,000, is the key to turning Tesla from a niche maker of expensive electric cars to a profitable, mass- market automaker. The company badly needs cash from the compact cars to deliver on CEO Elon Musk’s promise to post a net profit and positive cash flow in the third and fourth quarters. The company has had only two profitable quarters in its 15-year history.

To hit the 5,000-per-week mark, Tesla had to erect a second Model 3 assembly line under a tent outside its Fremont, California, factory, and Musk had to spend nights in the plant working out bugs with automation and other problems.

The company now says it expects to hit 6,000 Model 3s per week by late August, with its Model 3 assembly line under the plant’s roof reaching 5,000 on its own.

“The last 12 months were some of the most difficult in Tesla’s history,” the company’s statement said. Hitting the 5,000 mark “was not easy but it was definitely worth it,” the statement said.

Tesla critics now wonder if the company can keep up the 5,000-per-week rate, and they question whether it can build high quality vehicles underneath the heavy-duty tent on the site of what once was a joint-venture factory for General Motors and Toyota.

Dave Sullivan, manager of product analysis at the market research firm AutoPacific Inc. and a former manufacturing manager for Ford Motor Co., said reaching the 5,000-per-week won’t make Tesla profitable by itself. He predicted the company will have trouble sustaining the rate because parts suppliers will have difficulty keeping up and bottlenecks will develop in the body assembly and paint shops.