The Toyota Mirai is an electric car with an unusual answer to one of the central questions of electric mobility: where should the electricity come from?

Instead of relying primarily on a large battery charged from the grid, the Mirai carries compressed hydrogen and generates electricity onboard. Inside its fuel-cell stack, hydrogen reacts electrochemically with oxygen drawn from the surrounding air. The process creates the electrical current used to power the car and produces heat and water as byproducts.

That makes the Mirai a fuel-cell electric vehicle, or FCEV. Its wheels are driven by an electric motor, but its main energy source is hydrogen rather than electricity stored in a large externally charged battery.

The technology has been on public roads for more than a decade. Toyota launched the first Mirai in Japan in December 2014, followed by its U.S. arrival in 2015. The current second-generation model introduced substantial changes to the fuel-cell system, hydrogen storage and vehicle architecture.

The basic chemistry is straightforward even though making it work reliably inside a passenger car requires sophisticated engineering.

The Mirai uses a polymer electrolyte fuel cell. Hydrogen enters the anode side of the fuel cell, where a catalyst separates hydrogen molecules into positively charged protons and negatively charged electrons. The electrolyte membrane allows the protons to pass through but blocks the electrons.

Those electrons therefore travel through an external electrical circuit. That movement of electrons creates the electric current that can ultimately power the vehicle.

On the other side of the cell, oxygen from the air enters at the cathode. The protons, electrons and oxygen then combine to form water. The reaction also produces heat. There is no combustion inside the fuel cell.

Individual fuel cells produce relatively little voltage, so many cells are assembled into a stack. Toyota’s second-generation Mirai fuel-cell stack has a maximum output of 128 kilowatts, up from 114 kilowatts in the first generation. Toyota said the newer stack was also about 20% smaller and 50% lighter than its predecessor when the redesigned Mirai was introduced.

The result is essentially a compact onboard electricity generator that operates whenever the vehicle has hydrogen and air available.

Although hydrogen distinguishes the Mirai from a battery-electric vehicle, the actual propulsion system remains electric.

Toyota describes the 2026 Mirai as producing 182 horsepower through its fuel-cell electric powertrain. Electricity generated by the fuel cell, along with energy recovered through regenerative braking, works with a lithium-ion battery before power is delivered to the rear-mounted electric motor.

The battery therefore plays an important supporting role. It can store recovered braking energy and electricity from the fuel-cell system, helping the vehicle respond to changing power demands.

Hydrogen itself is stored in high-pressure, carbon-fiber-reinforced tanks. The current Mirai uses three tanks, an arrangement introduced with the second-generation car. Toyota’s technical review of that generation says the redesign increased hydrogen storage capacity from 4.6 kilograms to 5.6 kilograms while allowing the fuel-cell stack to move beneath the hood.

This architecture gives the Mirai characteristics associated with both electric and conventional cars. Its propulsion is electric, but replenishing its main energy supply involves filling tanks with hydrogen rather than plugging the vehicle into a charger.

For the 2026 Mirai, Toyota lists an EPA-estimated driving range of 402 miles when fully fueled. The company also lists EPA-estimated efficiency of 76 MPGe in city driving, 71 MPGe on the highway and 74 MPGe combined.

Those figures describe different things.

The 402-mile number is an EPA-estimated driving-range rating, not a guarantee of the distance every driver will achieve. Actual range varies with driving conditions and vehicle use.

MPGe, meanwhile, stands for miles per gallon of gasoline equivalent. It does not mean the Mirai consumes gallons of fuel. The U.S. Environmental Protection Agency uses MPGe to express the energy consumption of vehicles using fuels such as hydrogen or electricity in units comparable with the energy contained in gasoline. This allows vehicles powered by different forms of energy to be compared on a common basis.

Refueling can also be relatively fast compared with charging a battery from empty. The U.S. Department of Energy says fuel-cell electric vehicles can generally be fueled in about five minutes, although actual fueling conditions can vary by station and vehicle.

That combination of electric propulsion, long rated range and short refueling times helps explain the continuing interest in hydrogen vehicles. The more difficult issue is making the hydrogen conveniently available.

The Mirai demonstrates that a hydrogen fuel-cell passenger car can operate as a practical road vehicle. Building a large and dependable fueling network has proved more difficult.

In the United States, the Mirai remains highly geographically concentrated. Toyota’s 2026 fleet information states that the model is available only in California from select dealers, reflecting the limited reach of the public hydrogen network.

California has invested heavily in hydrogen infrastructure, but availability has not always meant reliability.

A joint California Energy Commission and California Air Resources Board assessment published in May 2026 reported that 50 light-duty hydrogen stations were open to the public as of September 2, 2025, while another 11 were temporarily non-operational. The agencies said average network availability during the preceding year was approximately 60%, citing maintenance issues, equipment failures and hydrogen supply disruptions.

The same assessment reported 14,128 light-duty FCEVs registered in California as of April 2025. Using the National Renewable Energy Laboratory’s Hydrogen Station Capacity Evaluation tool, the agencies estimated that the existing network at its observed availability could support about 34,300 vehicles. That is a modeled fueling-capacity estimate, not a count of vehicles actually served, and the report noted that geographic mismatches remained in places where vehicles were concentrated but fueling access had declined.

The California Energy Commission separately maintains a quarterly station database, with its published dashboard listing data through March 31, 2026 and directing drivers to a real-time system for current station status.

For hydrogen passenger cars, this infrastructure question is fundamental. A long vehicle range is less useful if the next functioning station is difficult to reach.

The Mirai’s fuel-cell reaction itself is unusually clean. When hydrogen is used in the fuel cell, water is the only tailpipe emission, alongside heat from the electrochemical process.

That does not mean all hydrogen has the same environmental impact.

Hydrogen is an energy carrier rather than a primary energy source. It has to be produced using energy from somewhere else. The U.S. Department of Energy identifies several production routes, including natural-gas reforming, electrolysis using electricity, biomass-based processes and other technologies.

As a result, the Mirai’s zero-tailpipe-emission status should be distinguished from the emissions associated with producing and distributing its hydrogen. Hydrogen made using low-carbon electricity can have a different upstream emissions profile from hydrogen produced using fossil fuels.

The vehicle itself therefore solves only one part of the equation. The carbon impact of a hydrogen transportation system also depends on how the fuel is produced, processed and delivered.

Toyota has been developing fuel-cell vehicles since long before the Mirai reached dealerships. When it launched the original model in 2014, the company said it had already spent more than two decades developing the technology.

The second-generation Mirai, introduced for the 2021 model year, represented a substantial redesign rather than a simple update. Toyota moved from front-wheel drive to a rear-wheel-drive platform, reduced the size and weight of the fuel-cell stack and increased hydrogen storage. The EPA-estimated maximum range rose by about 30% to 402 miles compared with the first-generation model.

For 2026, that 402-mile EPA-estimated range remains, while Toyota lists a starting U.S. MSRP of $51,795 before the stated processing and handling charge.

Yet the importance of the Mirai to Toyota increasingly extends beyond the sedan itself.

In October 2026, Toyota launched a new version of its hydrogen fuel-cell Sora bus and said it had supplied more than 3,500 fuel-cell systems to over 100 customers worldwide since 2019, for applications including buses, rail and stationary generators.

That broader activity shows how technology developed around fuel-cell vehicles can move into other parts of transportation and energy.

The Mirai illustrates a fundamentally different approach to running a car on electricity.

Rather than carrying most of that electricity in a large battery charged beforehand, it carries hydrogen and produces electricity as it travels. Hydrogen molecules surrender electrons inside the fuel-cell stack, those electrons create an electrical current, and oxygen ultimately combines with hydrogen ions and electrons to form water.

The result is a vehicle with an electric motor, 402 miles of EPA-estimated range and only water as a tailpipe emission, but one whose practicality remains closely tied to the availability and reliability of hydrogen fueling infrastructure.

After more than a decade on the market, that contrast still defines the Mirai. The technology inside the car demonstrates that hydrogen and oxygen can be used to generate electricity effectively on the road. The larger challenge is building the fuel supply system around it.