According to news agency Reuters, Tesla engineers told investors that the company would cut assembly costs by half in future generations of cars, but Chief Executive Musk did not unveil when it would debut a much-awaited affordable electric vehicle (EV).

Shares fell more than 5% in after-hours trade following the company's investor day at its Texas headquarters.

More than a dozen Tesla executives led by Musk discussed everything from a white-paper plan for the globe to embrace sustainable energy to the company's innovation in managing its operations from manufacturing to service.

The presentation featured an array of senior engineers, including the new global production chief, Tom Zhu, a nod to Tesla's attempt to show the depth of its executive bench beyond Musk, the face of the company.

Tesla's chief financial officer, Zach Kirkhorn, and others underscored their dedication to cutting production costs.

Kirkhorn estimated that Tesla should invest six times more than it has to date to hit its long-term target of increasing output to 20 million vehicles annually by 2030, a tenfold increase from current capacity. The bill could be $175 billion (R3 208 400 00), he reckoned.

The next investment step for the EV innovator will be a new Tesla factory in Northern Mexico, Musk said, announcing the first plant outside of the United States, Germany and China.