Hydrogen car bonus for BMW

The 3-Series coupe also gets new technology, a twin-turbo six-cylinder engine in the 335i model.

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 subsidised 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).

The company said engine power and torque remain the same regardless of the mode of operation, so switching from one mode to another has no effect on the driving behavior or performance.

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

Its overall cruising range exceeds 650km. Drivers can go 200km in hydrogen mode and another 450km in petrol mode.

"This technology is a viable solution until the hydrogen infrastructure is fully developed," the company said in a statement.

Yet for both carmakers and energy companies, hydrogen presents daunting challenges because it is one of the hardest fuels to store.

Meanwhile, BMW in New Zealand has launched its 3-Series coupe with an engine that has more to do with today's technology than tomorrow's.

The third generation coupe marks the introduction of the first ever twin-turbo petrol-powered engine in a production BMW as well as the arrival of pioneering direct injection fuel technology.

The flagship model is the two-door 335i, which uses the twin-turbo 3-litre petrol engine. It develops 225kw (306bhp) at 5800rpm and 400Nm of torque between 1300-5000rpm.

The 335i coupe accelerates from zero to 100km/h in 5.5 seconds (manual transmission) and has a top speed of 250km/h.

This level of performance, says BMW, is made possible through the use of two turbochargers, each supplying compressed air to three of the engine's six cylinders.

By using two smaller units BMW says it has developed an engine that reacts more quickly to changes in throttle position than traditional large-turbo applications.

This allows the engine to accelerate all the way to its 7000rpm red line and almost eliminates turbo lag, the delay experienced while larger turbochargers build up boost pressure.

The turbocharged engine is also considerably lighter than a normally aspirated engine of equal power - the twin-turbo six-cylinder weighs about 70kgs less than an eight-cylinder engine of corresponding performance. The 335i costs $119,900 for the automatic and $115,900 for the manual version. The 325i and its naturally asiprated engine starts at $93,900.