BMW is well advanced in the hydrogen combustion engine technology as they have developed a method of keeping the fuel tank at the required cool temperature for up to over a week. The major hurdle at this point is not so much technological but more to do with infrastructure, ie even if they were to launch a hydrogen car tomorrow, how would you refuel it? It will take years before governments take the initiative to develop a network of hydro fuel stations.

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August 2011 X5 3.0d