WELLINGTON – BMW is preparing to roll out a 7-Series sedan capable of running on either petrol or hydrogen.

The luxury German carmaker says it plans to build 100 or so BMW Hydrogen 7 cars and offer them to government and industry leaders, high-profile customers, movie stars and prominent figures mainly in Europe and the United States next year to tout the advantages of hydrogen.

"Crude oil is a limited resource, and we need to prepare alternative sources of fuel," said Christoph Huss, senior vice president for science and traffic policies at BMW in Munich.

BMW has tinkered with hydrogen technology since the 1970s and has considered producing hydrogen-powered fuel-cell cars, the path chosen by most carmakers.

But BMW executives opted to develop an internal combustion engine capable of running on hydrogen that would be clean yet still offer the satisfying driving performance its customers expect.

It has featured engines that run on hydrogen in its Clean Energy concept cars in recent years.

Mazda Motors Corporation is also testing petrol/hydrogen RX-8 sports cars in Japan. Ford Motor Co. has a concept car called the Model U featuring an internal combustion engine powered by hydrogen. General Motors Corp. is working on developing fuel-cell cars that run on hydrogen.

Hydrogen is potentially the cleanest fuel, but hydrogen-powered cars are currently impractical because there are very few hydrogen filling stations.

"We can't rely on an infrastructure that doesn't exist yet," Huss said.

With the BMW Hydrogen 7, drivers whose cars run low on liquid hydrogen can switch to conventional premium petrol by pressing a button.

"It gives customers a feeling of security," he said. The technology is very expensive, Huff said. "It is absolutely a subsidized project."

But the carmaker hopes to stoke interest in hydrogen technology among federal and local governments as well as energy companies. Automotive experts say BMW is also likely to derive indirect benefits by being the first to put hydrogen hybrids on the road.

"It creates an additional awareness of the brand and it ties that connection between BMW and innovation," says Alexander Edwards, automotive consultant at Strategic Vision in San Diego.

Innovation is a key selling point in the luxury car business, he said.

Toyota Motor Corp. has benefited by being a leader in developing and marketing petrol-electric cars, and the Japanese carmaker will introduce a hybrid version of its flagship Lexus LS sedan this year.

The term "hybrid" commonly refers to vehicles with two propulsion systems, such as the fuel-efficient Toyota Prius with its electric and petrol engines.

BMW also is developing such petrol-electric vehicle technology with DaimlerChrysler and GM.

By contrast, its BMW Hydrogen 7 car has one 12-cylinder engine that can run on two fuels and delivers 195kW (260bhp).

When the car is running in hydrogen mode, it emits essentially nothing but water vapor.

(www.nzherald.co.nz)