Right, before you start, this is NOT another one of those 'oh look, says 'ere I can run my car on water' posts, I know the laws of physics deem this impossible and it is a complete scam.
What I am asking instead is the fuelling requirements of a traditional petrol engine when running on pure hydrogen? I would hazard a guess at it being something like LPG, i.e. around 60% increase in specific fuel consumption?
I do not know the properties with regards to energy content etc of hydrogen as a fuel compared to petrol to make an educted guess.
Anyone know a bit more than myself care to share their thoughts?