Tesla Cybercab EPA Specs Declassified: 48 kWh Battery, 418-Mile Test Range, and a Curb Weight That Demands Explanation

Source: Electrek / EPA Certification Summary (June 15, 2026)  |  Published: June 16, 2026  |  Category: Tesla / Cybercab

The Government Document That Answers the Questions Tesla Hasn't

Since Tesla unveiled the Cybercab and began production at Giga Texas, the company has been characteristically sparse with official technical specifications. EPA certification filings don't wait for product launches. On June 15, 2026, Electrek surfaced the EPA's official Certification Summary Information for the Cybercab — test group TTSLV00.0L1A — and for the first time, the engineering parameters of Tesla's purpose-built Robotaxi are a matter of public administrative record.

The numbers confirm some of what Musk has promised. One number — the curb weight — is generating significant discussion among automotive engineers.


1. Battery: 47.6 kWh at 326V

The Cybercab's battery pack is specified at 326 volts nominal voltage and 146 ampere-hours capacity, yielding a total usable energy of approximately 47.6 kWh. This is a single lithium-ion pack — no dual-pack configuration.

Parameter Cybercab Model 3 RWD (for reference)
Battery voltage 326V ~350V
Capacity 146 Ah ~170 Ah
Total energy ~47.6 kWh ~57.5 kWh
Pack configuration Single pack Single pack

At 47.6 kWh, the Cybercab carries approximately 17% less energy than a standard Model 3. The fact that it achieves dramatically better range efficiency — as the MCT numbers confirm — is a direct result of its aerodynamic optimization and minimal passenger load design.


2. Range: 418.2 Miles MCT — What It Means in Practice

The EPA's Multi-Cycle Test (MCT) results for the Cybercab are exceptional:

Test Cycle Range
MCT Combined 418.2 miles (673 km)
MCT Highway 375.4 miles (604 km)

MCT figures are laboratory test results conducted under controlled conditions. Real-world range — accounting for temperature variation, passenger load, HVAC use, and driving style — typically runs 15–25% below MCT figures. Applying a 25% real-world discount to the 418.2-mile MCT result yields approximately 313 miles — which aligns precisely with Musk's stated target of 300 miles of real-world range.

Efficiency context: 418.2 miles from 47.6 kWh implies an MCT efficiency of approximately 8.8 miles per kWh. For comparison, the Model 3 Long Range achieves approximately 4.5–5.0 miles per kWh. The Cybercab's efficiency is nearly double — a result of its purpose-built aerodynamic design, minimal interior mass, and two-seat configuration.

3. Motor: 163 kW Front-Wheel Drive

The Cybercab uses a single 163 kW (219 hp) AC three-phase permanent magnet synchronous motor driving the front wheels. The front-wheel-drive configuration is a deliberate engineering choice for a vehicle optimized for urban and suburban Robotaxi operation:

FWD Advantage for Robotaxi Use Detail
Simplified drivetrain Single motor, no rear differential — lower manufacturing cost and fewer failure points
Weight distribution Front-heavy layout optimized for urban low-speed maneuvering
Power adequacy 163 kW is sufficient for urban Robotaxi speeds; performance is not the design priority

4. The Curb Weight Question: 3,113 lbs for a Two-Seat Car

The most discussed number in the EPA filing is the curb weight: 3,113 lbs (1,412 kg). For context:

Vehicle Seats Battery Curb Weight
Tesla Cybercab 2 47.6 kWh 3,113 lbs
Tesla Model 3 RWD (refreshed) 5 ~57.5 kWh ~3,862 lbs
Weight difference −3 seats −10 kWh −749 lbs

The Cybercab has three fewer seats, approximately 10 kWh less battery, no steering wheel, no brake or accelerator pedals, and no conventional instrument cluster — yet it weighs only 749 lbs less than a five-seat Model 3. For automotive engineers, this gap demands explanation.

Where the Weight Is Going

The engineering community's analysis points to three categories of mass that are unique to a purpose-built autonomous vehicle:

1. Structural redundancy for driverless crash protection. In a conventional vehicle, the driver's presence and reaction time are part of the crash mitigation system. In a fully autonomous vehicle with no driver, the structural cage must absorb crash energy without any human pre-bracing or evasive action. This requires heavier structural reinforcement in the A-pillar, B-pillar, and floor pan.

2. Steer-by-wire dual redundancy. The Cybercab's steer-by-wire system — which eliminates the mechanical steering column entirely — requires dual-redundant servo actuators, redundant control electronics, and redundant power supplies for each steering axis. Each redundant system adds mass that a conventional steering column does not require.

3. AI compute platform with liquid cooling. The HW4/AI4 compute stack that runs Cybercab's autonomous driving system generates significant heat under continuous operation. The liquid cooling infrastructure — heat exchangers, coolant loops, pumps, and thermal management hardware — adds mass that a conventional vehicle's passive cooling does not.

The efficiency paradox: The same engineering decisions that add weight — steer-by-wire, autonomous compute, structural redundancy — also enable the aerodynamic optimization and interior simplification that produce the 8.8 miles/kWh efficiency figure. The Cybercab is heavy for its size precisely because it is built to operate without a driver. The efficiency comes from everything else that was removed.

5. The Commerce Date: May 29, 2026

The EPA filing's most commercially significant field is the "Introduction into Commerce Date": May 29, 2026. This is not a production start date or a delivery date — it is the date on which the Cybercab became legally authorized for sale and commercial operation in the United States.

Tesla's Cybercab officially entered production at Giga Texas in April 2026. The first Cybercab batch was hauled by Tesla Semi, signaling the imminent launch of the Robotaxi era. The May 29 commerce date — one day after Texas SB 2807 took effect authorizing commercial driverless vehicle operation statewide — confirms that Tesla coordinated its regulatory certification timeline with the legislative calendar.

As with the Tesla Semi's CARB filing that revealed its 822 kWh battery pack, the EPA certification process has once again provided the public with technical specifications that Tesla has not formally announced — a pattern that reflects how regulatory transparency requirements interact with Tesla's characteristically minimal official communications.