[2][3] As of 2021[update], there were two models of hydrogen cars publicly available in select markets: the Toyota Mirai (2014–), the first commercially produced dedicated fuel cell electric vehicle (FCEV),[4][5][6] and the Hyundai Nexo (2018–).

[9] Various technologies are being developed that aim to deliver costs low enough, and quantities great enough, to compete with hydrogen production using natural gas.

[11][12][13] In addition, leaked hydrogen is an invisible, highly flammable gas and has a global warming effect 11.6 times stronger than CO₂.

[14] The rationale for hydrogen vehicles lies in their potential to reduce reliance on fossil fuels, associated greenhouse gas emissions and localised air pollution from transportation.

[citation needed] For first stages, dense fuelled rockets in studies may show a small advantage, due to the smaller vehicle size and lower air drag.

[27] With the rapid rise of electric vehicles and associated battery technology and infrastructure, the global scope for hydrogen's role in cars is shrinking relative to earlier expectations.

[32] The Toyota FCHV and Honda FCX, which began leasing on December 2, 2002, became the world's first government-certified commercial hydrogen fuel cell vehicles,[16][15][33] and the Honda FCX Clarity, which began leasing in 2008, was the world's first hydrogen fuel cell vehicle designed for mass production rather than adapting an existing model.

[39][40][41] However, due to high prices and a lack of charging infrastructure, sales fell far short of initial plans, with only 273 units sold by the end of May 2015.

[43] Toyota launched the world's first dedicated mass-produced fuel cell vehicle (FCV), the Mirai, in Japan at the end of 2014[4][5][6] and began sales in California, mainly the Los Angeles area and also in selected markets in Europe, the UK, Germany and Denmark[44] later in 2015.

[66] Companies such as Boeing, Lange Aviation, and the German Aerospace Center are pursuing hydrogen as fuel for crewed and uncrewed aeroplanes.

"[68] In July 2010, Boeing unveiled its hydrogen-powered Phantom Eye UAV, powered by two Ford internal-combustion engines that have been converted to run on hydrogen.

[69] As of 2019[update] hydrogen fuel cells are not suitable for propulsion in large long-distance ships but are being considered as a range-extender for smaller, short-distance, low-speed electric vessels, such as ferries.

It used a 2.0 litre, 43 kW (58 hp) diesel internal combustion engine converted to use hydrogen as a fuel with the use of a compressor and direct injection.

[84] In March 2015, China South Rail Corporation (CSR) demonstrated the world's first hydrogen fuel cell-powered tramcar at an assembly facility in Qingdao.

[97] Its SURUS (Silent Utility Rover Universal Superstructure) is a flexible fuel cell electric platform with autonomous capabilities.

Since April 2017, the U.S. Army has been testing the commercial Chevrolet Colorado ZH2 on its U.S. bases to determine the viability of hydrogen-powered vehicles in military mission tactical environments.

[107][108] A record of 207.297 miles per hour (333.612 km/h) was set by a prototype Ford Fusion Hydrogen 999 Fuel Cell Race Car at the Bonneville Salt Flats, in August 2007, using a large compressed oxygen tank to increase power.

[47] In 2020, researchers at the University of Copenhagen's Department of Chemistry are developing a new type of catalyst that they hope will decrease the cost of fuel cells.

"[118] The problems in early fuel-cell designs at low temperatures concerning range and cold start capabilities have been addressed so that they "cannot be seen as show-stoppers anymore".

[120] Studies using neutron radiography on unassisted cold-start indicate ice formation in the cathode,[121] three stages in cold start[122] and Nafion ionic conductivity.

[128] A suggested benefit of large-scale deployment of hydrogen vehicles is that it could lead to decreased emissions of greenhouse gases and ozone precursors.

As of September 2023, hydrogen cost $36 per kilogram at public fueling stations in California, 14 times as much per mile for a Mirai as compared with a Tesla Model 3.

[142] In 2018, researchers at CSIRO in Australia powered a Toyota Mirai and Hyundai Nexo with hydrogen separated from ammonia using a membrane technology.

The IEA deems the infrastructure requirements for hydrogen in shipping more challenging, drawing attention to the "need for major investments and co‐ordinated efforts among fuel suppliers, ports, shipbuilders and shippers".

To enable the commercialization of hydrogen in consumer products, new codes and standards must be developed and adopted by federal, state and local governments.

[150] The New York State Energy Research and Development Authority (NYSERDA) has created incentives for hydrogen fuel cell electric trucks and buses.

[154][155] Former U.S. Department of Energy official Joseph Romm has said: "A hydrogen car is one of the least efficient, most expensive ways to reduce greenhouse gases.

Considering all the obstacles and requirements for new infrastructure (estimated to cost as much as $400 billion), fuel-cell vehicles seem likely to be a niche technology at best, with little impact on U.S. oil consumption.

[28] A 2023 study by the Centre for International Climate and Environmental Research (CICERO) estimated that leaked hydrogen has a global warming effect 11.6 times stronger than CO₂.

[170] In 2024, Hyundai recalled all 1,600 Nexo vehicles sold in the US to that time due to a risk of fuel leaks and fire from a faulty "pressure relief device".