On the Berlin Ring, our BMW 7-Series is surging down the autobahn in H2 mode and it is emitting no carbon dioxide, only water vapour.
We are, an executive says, "pioneers of the hydrogen economy". Or are we?
The German car group has just launched its Hydrogen 7, the world's first luxury saloon powered by liquid hydrogen that, it claims, is suitable for everyday use.
BMW executives say that hydrogen is the only source of energy with the potential - in the long run - to replace fossil fuels in road traffic and, in the short term, the carmaker is betting its technological future on liquid hydrogen as an alternative fuel in the expectation that global oil reserves will run out.
But BMW's executives admit there are serious snags with this model that can produce 260bhp through its six-litre, 12-cylinder engine and can reach 229km/h.
First, it is going to be expensive; far more so than the current range of 7-Series. The first 100 Hydrogen 7s are to be leased to "eco-friendly" celebrities such as Madonna or Al Gore.
Executives go unusually silent when pressed to outline plans for mass production, saying their aim is to give signals to the outside world to press ahead with research into hydrogen-powered models, to build up an infrastructure capable of sustaining them and to adopt harmonised taxation that will encourage consumers to switch to them.
There are only five filling stations in Germany equipped to provide the hydrogen for the car's 170-litre tank. It takes more than five minutes to pump the eight kilos of hydrogen the tank will hold and at the Total station outside Charlottenburg, it costs €64.
Driving normally in hydrogen mode will take the car 200km - or the equivalent of 85 litres per 100km.
It's easy to switch to petrol mode, adding 500km to the car's range at a rate of consumption of 6.75km a litre - further denting its "dynamic efficiency" pretensions and prompting Der Spiegel to label it "a pseudo-green gas-guzzler".
Timm Kehler, in charge of marketing, concedes that, although the car's technology is mature, the surrounding infrastructure is immature. Fellow executives also admit that it would cost €23bn to equip enough service stations to cover the country's hydrogen needs.
More tellingly, the production of hydrogen - primarily from oil and gas now - will add 30 per cent more carbon dioxide emissions.
Executives insist, however, that it will be increasingly produced from renewable sources leading to an 80 per cent cut in emissions.
Ivan Holdac, secretary-general of the European Automobile Manufacturers Association (ACEA), the industry lobby fighting EU plans for green legislation, says the only way forward is to boost demand.
The way to do this, he says, is through harmonised taxes and a common infrastructure to enable manufacturers to exploit economies of scale.
- Guardian News Service