Against all odds, the Tesla Cybercab is in production. And while Elon Musk’s company may not have a very coherent plan for the tiny, autonomous two-seater, it’s still taking the necessary steps to certify the EV’s legitimacy. As such, Tesla recently filed paperwork with the Environmental Protection Agency that reveal many of the Cybercab’s specs, including its weight, battery size, and preliminary range estimates.

What these documents reveal is the lightest, most range efficient vehicle Tesla has ever produced — and quite possibly one of the most efficient EVs ever produced.

The EPA filings confirm the Cybercab runs on a single front-mounted 219 horsepower permanent magnet motor with front-wheel drive, a compact 48 kWh battery pack running at 326 colts, and a curb weight of just 3,113 pounds — making it roughly 700 pounds lighter than the lightest Model 3 on the market. The certificate, which was filed May 21st and first noticed by Car and Driver, is required of all vehicles before they’re allowed to be sold in the US.

At 3,113 pounds, the Cybercab is remarkably light, likely because Tesla has stripped out the steering wheel and many of the traditional controls that aren’t necessary in a vehicle that’s intended to be fully autonomous. Most EVs are notoriously heavy because they require massive battery packs to achieve a 300-mile-plus range. The cool thing about the Cybercab is that it manages to weigh roughly the same as a gas-powered compact car while still carrying a relatively heavy lithium-ion battery.

The weight reduction also allows Tesla to achieve unprecedented efficiency, squeezing maximum range out of a tiny battery pack. According to the raw numbers filed with the EPA, the Cybercab is listed as having 418 miles of range. Once these unadjusted lab numbers go through EPA testing, the real world range is likely to drop to around 290-300 miles, which closely aligns with what Tesla said it was targeting for the vehicle.

The Cybercab achieves a rating of 165 Watt-hours-per-mile, making it the most efficient EV on the market today. By comparison, the Lucid Air — previously considered to be the most efficient EV — gets 230Wh/mi. With that efficiency rating, the Cybercab can travel roughly 6 miles on a single kilowatt-hour of power, which is great news for a company that intends to operate these vehicles for about 20 hours a day. Compare that to standard EVs that get closer to 3 or 4 miles per kWh.

What’s still missing, though, is a real plan for putting these cars in operation. As of the time of publication, Tesla is running less than 60 Model Y robotaxis in a handful of Texas cities — despite Musk claiming that they would be available to half the US population by the end of 2025. Tesla is actively seeking permits to launch a service in Las Vegas, as well as several cities in Florida. But the company still hasn’t said when it expects to put the Cybercab into operation.