New York (CNN Business) Tesla's stock enjoyed its biggest spike in six years this week after the automaker reported an unexpected third quarter profit. But that might not have been the biggest achievement for the company.

What could end up being far more important is that the Model Y, the electric car company's lower priced SUV, is now due to go into production by next summer. It had previously been projecting to start production in the fall of 2020.

"There may be some room for improvement there, but we're confident about summer 2020," said CEO Elon Musk about the company's new time frame.

Tesla TSLA If that doesn't seem like that big of a change, keep in mind two facts aboutand the Model Y

First, the company's track record of meeting internal deadlines for rolling out new cars has been particularly bad. At times, it has been years late in delivering promised production of new vehicles. Moving a deadline up, not back, is big news at Tesla.

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