Elon Musk said Tesla's older cars don't have fully autonomous driving capabilities. Newsday LLC/Getty Images Elon Musk made several promises over the years that the Teslas people buy will be fully autonomous. Turns out there's now a cut-off for how old the Teslas can be for it to have full autonomy. The CEO said Teslas with the previous-gen HW3 computer won't be fully autonomous. Tesla owners may want to double-check the hardware inside their cars — a lot of them might not have fully autonomous driving capabilities. CEO Elon Musk said on Wednesday during the first-quarter earnings call that Teslas with Hardware 3, or HW3 for shorthand, will not be able to get unsupervised Full Self-Driving (FSD) with an over-the-air software update. That means Teslas, roughly between the model years of 2019 and 2023, will have an internal computer that's too outdated to get access to one of the key features Musk is betting the company's future on. "I wish it were otherwise, but Hardware 3 simply does not have the capability to achieve unsupervised FSD," Musk said during the call. "We did think at one point it would have that, but relative to Hardware 4, it has only 1/8 of the memory bandwidth of Hardware 4. Memory bandwidth is one of the key elements needed for unsupervised FSD." Tesla and Musk have made repeated promises to consumers over the years, even before the release of Hardware 3, that their cars would be fully autonomous. A 2016 blog post from Tesla, retrieved via the Wayback Machine, said that "all Tesla vehicles produced in our factory — including Model 3 — will have the hardware needed for full self-driving capability at a safety level substantially greater than that of a human driver." The blog ends by saying that "as always, our over-the-air software updates will keep customers at the forefront of technology and continue to make every Tesla, including those equipped with first-generation Autopilot and earlier cars, more capable over time." In 2016, Musk said in a press call: "The foundation has been laid for fully autonomous, it's twice as safe as a human, maybe better." Now, he said older customers must upgrade their vehicles to achieve fully autonomous driving. Musk said in the Wednesday call that all customers using Hardware 3 would be able to do a "discounted trade-in" to upgrade the car's computer. They will also have to replace the cameras on the cars to go with Hardware 4. For this large-scale upgrade operation, Musk said Tesla will have to set up "small factories in major metropolitan areas," because doing it at service centers would be too inefficient. "So we basically need like many production lines to make the change," he said. Tesla reported a total first-quarter revenue of $22.38 billion — a 16% increase compared to the year before, beating analysts' estimates. Representatives for Tesla did not respond to a request for comment from Business Insider. Read the original article on Business Insider