Further development for hydrogen internal combustion
engines is needed in several areas including
development of injection equipment that meets automotive
durability requirements, assessment of efficiency
potential of advanced mixture formation concepts on
multicylinder engines, as well as demonstration of realworld
fuel economy and tailpipe emissions of advanced
prototype vehicles. In addition to those areas related
directly to engine research and development, critical
improvements in on-board hydrogen storage density have
to be achieved. Finally, the dual-fuel capability of
hydrogen internal combustion engine vehicles might
help to overcome the chicken-and-egg problem regarding
the timing of introduction of infrastructure versus vehicle
deployment.