The H2H features the same Vortec 6000 (6.0-liter V-8) engine utilized in all HUMMER H2s on the road today. This experimental vehicle achieves much of the same on-road driving characteristics and comfort of the H2, a major accomplishment for such an advanced technological effort.

The dynamics of fuel delivery to an internal combustion engine are much different for gaseous hydrogen fuel, compared to gasoline, due to the different combustion dynamics of these fuels. Specially designed fuel injectors deliver hydrogen to the engine more conservatively than in a gasoline fuel system, thus reducing engine power. The H2H adds a supercharger mounted onto the Vortec 6000 to help the engine reclaim some of that deficit, reaching a peak of approximately 180 horsepower (134 kw).

The truck’s powertrain, fueling and electrical systems have all been extensively reconfigured to operate with a dedicated 350-bar compressed hydrogen fuel system. This includes three on-board carbon fiber fuel tanks. Two tanks are mounted underbody in the approximate location of a traditional gasoline fuel tank. The third is mounted in the H2 SUT’s rear cargo bed. The three tanks combine to create 5.5 kg (12 pounds) of total hydrogen storage.

The H2H’s hydrogen fuel system including fuel injection, electronic controls, ultra-light composite hydrogen storage, complete with integral pressure regulation and safety systems, was developed in collaboration with Quantum Technologies (NASDAQ: QTWW), a California-based leader in packaged fuel systems for hydrogen and one of GM’s fuel cell technology alliance partners. In 2002, GM acquired a substantial minority ownership position in Quantum to collaborate on improving the range of GM’s fuel cell vehicles through the development of hydrogen storage, hydrogen handling and electronic control technologies for fuel cell applications.

The hydrogen refueling interface for the H2H follows the prototype design set forth in California. It consists of two connectors (one in the traditional fuel-fill location, the other on the rear bumper) that enable the fastest fuel fill currently available in California’s growing hydrogen infrastructure. In its early testing and development, it is estimated that the H2H can travel roughly 60 miles (97 km) between fill-ups.

GM’s foremost powertrain and vehicle development engineers in the U.S., Canada and Germany collaborated to create the H2H’s hydrogen fuel system. The electronics and safety systems of the H2H are state-of-the art for a hydrogen-powered vehicle. In fact, the H2H’s safety system is modeled after that used on GM’s Hydrogen3 minivan, GM’s record-setting hydrogen fuel cell vehicle.

GM is moving very fast on reducing the cost of fuel cell stacks and proving technology and commercial viability of fuel cell technology, and is committed to perfecting fuel cells because they are more efficient and cleaner than internal combustion engines. Therefore, there are no plans at GM to produce the H2H or pursue hydrogen internal combustion engine technology long term.