Tesla's chief has promised profitability this year and said investors won't need to prop the EV maker up.

According to Reuters, in a tweeted response to a story in The Economist, which cited estimates Tesla would need US$2.5bn to $3bn this year in additional funding, CEO Elon Musk said: "The Economist used to be boring, but smart with a wicked dry wit. Now it's just boring (sigh). Tesla will be profitable & cash flow+ in Q3 & Q4, so obv no need to raise money."

An unprecedented level of robots used in the Model 3's final assembly, in a break with automotive manufacturing norms, has added complexity and delays, which Musk acknowledged.

"Excessive automation at Tesla was a mistake," Musk tweeted, according to Reuters. "To be precise, my mistake. Humans are underrated."

Thomson Reuters consensus of analyst estimates predicts Tesla's free cash flow to be negative well into 2019, thanks in part to heavy investments. Only one of 19 analysts covering the stock see positive adjusted earnings per share in the third quarter, with that number growing to four for the fourth quarter.

Wall Street brokerage Jefferies, which provided the funding estimate cited by The Economist, said in a recent note it expected refinancing risk to remain high for Tesla until it could consistently produce 10,000 Model 3s a week, Reuters noted.

The company again missed its own 2,500 target for weekly production at the end of the first quarter, and analysts and fund managers doubt Tesla's ability to keep production growing to a promised 5,000 Model 3s per week in three months time.

He told "CBS News" in an interview cited by Reuters the company "got complacent" and "put too much new technology into the Model 3 all at once".