BMW is starting production of its emission-free 7-series, the Hydrogen 7.
Around 100 Hydrogen 7s will be built in 2007, but you won't be able to buy one. BMW plans to lease the cars to selected drivers, to help it in its research into this new fuel technology.
The Hydrogen 7 uses a 12-cylinder internal combustion engine that can also run on petrol. It needs to – the car's range on hydrogen alone is around 125 miles. A standard 74-litre petrol tank gives an extra 300-mile range. Indeed, one of the car's problems will be the availability (or rather unavailability) of hydrogen fuel.
When running on hydrogen, the 7's only emission is water vapour. Power is the same whether running on petrol or hydrogen, but it's much lower than in a standard 760i, at 256bhp against 445bhp. Still, the Hydrogen 7 will accelerate from 0-62mph in 9.5sec, and hit a maximum of 143mph.
We've also just driven the Hydrogen 7. Click here to read what it's like.