Elon Musk, chief executive of Tesla Motors, with the Model X prototype on Thursday.Jerry Garrett for The New York TimesElon Musk, chief executive of Tesla Motors, with the Model X prototype on Thursday.

HAWTHORNE, Calif. — On Thursday, Tesla Motors unveiled a prototype of its third vehicle, the Model X, here at the company’s design studios. Elon Musk, the chief executive of the electric-vehicle start-up, said the crossover-like car would enter production in late 2013.

“This is kind of the killer app for families,” Mr. Musk said of the X in an interview after a preview for media. “It has more utility than a minivan, and better performance, much better performance, than an S.U.V.”

With a shape evocative of recent premium crossovers like the Acura ZDX and BMW 5 Series Gran Turismo, the Model X fits within a popular niche. Its copious interior space, however, aligns it more closely with minivans and S.U.V.’s.

“Because it is an electric car, and we don’t have to package a traditional internal combustion engine powertrain, we have available to us much more packaging opportunities,” Mr. Musk said.

The new model was shown weeks after the announcement of two high-ranking engineers’ departures sent Tesla’s stock price falling sharply before it rebounded the following week. News of the Model X also came days after Fisker Automotive, another start-up, announced it would not meet sales benchmarks outlined by the Energy Department in the $529 million loan it extended to the company in 2009, and would lay off dozens of workers. Tesla received a loan of $465 million from the department that same year.

Problems with cash flow plagued Tesla as it tried to deliver its first product, the Roadster, but contracts to supply electric power trains to companies like Daimler and Toyota, as well as a lucrative I.P.O. in 2010, have given the company more solid financial footing.

The Model X evokes other premium crossovers, particularly the Acura ZDX and BMW 5 Series Gran Turismo.Jerry Garrett for The New York TimesThe Model X evokes other premium crossovers, particularly the Acura ZDX and BMW 5 Series Gran Turismo.

A signature feature of the Model X, destined for the production model, Mr. Musk said, was the so-called falcon-wing doors for rear passengers. Like a traditional gullwing door, they open upward, but a hinge in the middle allows the leading edge of the door to remain tucked closely to the car.

“You can get in and out in the tightest garage or parking spot without hitting the wall or car next to you, or your head,” Mr. Musk said.

The Model X has two trunks: one in the rear and another under up front, where the engine would otherwise be found. “Some S.U.V.’s and minivans claim to have room for seven passengers,” Mr. Musk said. “But if you fill them with people, there is no room for their luggage. The Model X offers ample room for seven adults, and their luggage.”

Like the Model S sedan, which is expected to arrive in showrooms this summer after numerous delays, the Model X conceals its batteries in the platform of the car. Electric motors spin the front and rear wheels independently. “It has an innovative all-wheel-drive system that is incredibly precise and accurate in its application of power and traction, much more so than any other type of all-wheel-drive out there,” Mr. Musk said.

The Model X shares about 60 percent of its content with the Model S and weighs about 10 percent more. As a result, Mr. Musk said, the X would squeeze roughly 10 percent less range from its battery packs. The X would be offered with a choice of two packs, rated at 60 and 85 kilowatt-hours. For comparison, Tesla estimates a Model S can travel 160-300 miles on a full charge, depending on battery-pack specification.

“Even though the X is heavier, it will still go zero to 60 miles an hour in about 4.4 seconds,” Mr. Musk said. “And that’s not even the Performance model.” Pricing should be close to Model S territory, he added. That model starts at $49,900 after a $7,500 federal tax credit, but the price can approach $100,000, depending on options.

“This will be our most important, and highest-volume car, when it comes out,” he said. A fourth model, aimed at a lower price point and wider audience, would likely be announced in 18 to 24 months, he added.

The prototype's interior, with a central digital interface similar to that found in the Model S.Jerry Garrett for The New York TimesThe prototype’s interior, with a central digital interface similar to that found in the Model S.

By JERRY GARRETT