Many experts consider hydrogen to be the fuel of the future. They see converting it into electrical energy, which is then stored in batteries until required; the actual drive is then provided by an electric motor. By contrast, BMW spent many years optimizing internal combustion engines for use with hydrogen. The high point of this development was the speed records set by the futuristic H2R in 2004, which exceeded 185 mph. The BMW Group achieved this following a comprehensive research program into hydrogen technology – from filling and storage at 423° below zero, to combustion. Among other reasons, BMW abandoned the combustion principle for hydrogen on account of the high fuel losses during storage and conversion, and the records were consigned to the annals of technical history. Nevertheless, a great deal of expertise and several valuable patents survived the period, and could well make a reappearance in future developments.