The numbers were sitting in a federal filing all along. Environmental Protection Agency documents posted this week disclose the full technical specifications of Tesla’s Cybercab, the robotaxi the company unveiled in 2024 and plans to build at its Texas factory: a curb weight of 1,413 kilograms, 219 horsepower, and a 48-kilowatt-hour battery pack. None of the figures surprised Tesla watchers, but together they explain the vehicle’s business case better than any marketing event.
The weight is the story. The Cybercab’s 1,413 kilograms is roughly 300 kilograms lighter than a Model 3, Tesla’s smallest current car, and that gap drives everything else. A lighter vehicle needs fewer battery cells, which cuts the cost of the pack; it wears tires and brakes more slowly, which cuts maintenance; and it uses less energy per mile, which cuts the electricity bill on every fare. For a vehicle designed to be driven nearly around the clock, those savings compound into the unit economics that determine whether robotaxis can undercut human-driven rides.
The 219-horsepower figure is modest by Tesla standards — the company sells sedans with three times that output — but the Cybercab was never meant to win drag races. Its job is to move one or two passengers through city streets at legal speeds, and the power rating is enough for that, with margin for hills and air conditioning. Engineers familiar with robotaxi programs say the more relevant spec is the energy density of the pack: 48 kilowatt-hours in a vehicle this light suggests the company is using its newest battery chemistry rather than reusing older cells.
The 48-kilowatt-hour battery deserves attention for what it implies about cost. Tesla’s own analysis, presented when the vehicle was unveiled, put the cost per mile of a robotaxi below the cost of running a conventional car, and a pack a third the size of the Model 3’s is central to that arithmetic. Fewer cells also means the vehicle is cheaper to replace at end of life, an important factor for a machine expected to log hundreds of thousands of miles in fleet service.
The filings also confirm the vehicle’s stripped-down design. The Cybercab has no steering wheel and no pedals, a configuration that required federal approval and that Tesla has been negotiating with regulators since the prototype appeared. The EPA documents do not settle the regulatory question — that lives with the National Highway Traffic Safety Administration — but they mark a step in the certification process that must conclude before production units can be sold.
Production timing remains the open variable. Tesla has said it aims to start building the Cybercab at its Texas plant, where the company has been preparing a new assembly line, and executives have pointed to this year as the start of volume. The EPA filing is consistent with that schedule: automakers typically file certification documents in the months before a vehicle enters production, though delays are common.
The competitive frame matters as much as the hardware. Waymo, the current leader in U.S. robotaxis, operates purpose-built and retrofitted vehicles in a handful of cities, with economics that remain opaque. Tesla’s pitch is different: build a vehicle whose cost structure makes robotaxi fares cheap enough to compete with bus fares, then deploy it through a network of owners who put their cars into the service when not in use. The Cybercab’s spec sheet is the first hard evidence that the cost structure is real.
Skeptics note what the filings do not show. There is no range figure in the documents — Tesla has not published one — and 48 kilowatt-hours, while fine for city duty, is far below what any consumer vehicle offers, which is precisely the point: the Cybercab is not a consumer vehicle. The absence of a steering wheel, meanwhile, raises questions about how the vehicles will be serviced, cleaned and recovered when a fare goes wrong, logistics that no spec sheet answers.
The market’s reaction was muted, with Tesla shares moving little on the news, a sign that investors have already priced in the robotaxi program’s promises and are waiting for production numbers. The specifications, though, settle a debate inside the industry about whether Tesla would cut costs aggressively enough to make the robotaxi business work: the answers, 1,413 kilograms and 48 kilowatt-hours, say yes.
The EPA filing also resolves a small question about the vehicle’s positioning. Some observers had speculated that Tesla would build the Cybercab on its next-generation platform with structural batteries and large single-piece castings; the documents are consistent with that approach, though they do not say so explicitly. What they do confirm is that Tesla is proceeding through the standard certification pipeline, a process the company has sometimes skipped in favor of building first and filing paperwork later. The order of operations matters for the production timeline, and the filing suggests the company intends to sell the vehicle commercially rather than operate it only inside its own network.
For now, the Cybercab exists as a set of numbers in a government file. If Tesla hits its production targets, those numbers become the foundation of a fleet; if it misses them, they become a footnote. Either way, the vehicle’s design has already done something unusual in the auto industry — it was engineered for a business model, not for a buyer.
