By Jorn Madslien
Business reporter, BBC News, Frankfurt motor show
Flextreme is powered by batteries
Cleaner diesel and petrol-electric hybrid engines take centre stage at this week's motor show in Frankfurt, as the industry sets out to explain how it will reduce the harmful emissions from the cars they make.
"It is partly due to environmental concerns, partly due to energy concerns," Rick Wagoner, chief executive of General Motors (GM), told BBC News in an interview on the sidelines of an event on Monday.
Most industry officials believe technological solutions offer the best way forward, though many are displaying concept cars that show their visions for the future rather than production models that customers can buy.
Monday night, GM unveiled its Flextreme concept vehicle, which runs on batteries that can be either charged using mains electricity or a conventional petrol or diesel engine, thus pinning its hope on a breakthrough in battery technology.
Others, including all the upmarket German carmakers Audi, BMW, Mercedes and Porsche, are displaying their own versions of cars powered by the sort of petrol-electric hybrid engines initially pioneered by Toyota and Honda.
Toyota president Katsuaki Watanabe said he welcomed the way its rivals were moving towards hybrid technology, in response to a question by the BBC at a dinner on Monday night.
Such "healthy competition" should benefit the environment, he insisted, though he also pointed out that "at the moment, Honda is the only other company with a hybrid vehicle" (that it has developed on its own).
The competition is also motivating Toyota to push the boat out further.
"Hybrid technology is the cleanest technology available on the market today," insisted Toyota's head of research and technology, Masatami Takimoto during Monday's event - where Toyota was showing off a plug-in hybrid that uses mains electricity to top up the battery.
"To realise hybrid-market growth, we will continue to improve our hybrid technology in every way."
But although a growing number of carmakers have come to see petrol-electric hybrids as both viable and desirable instruments in their efforts to reduce harmful emissions, they are not turning their backs on efficient diesel engines.
Some analysts portray the situation as a hybrid versus diesel battle, though as a matter of fact, most companies are involved in developing both the technologies.
Ford, Opel and Volkswagen, as well as BMW and Mercedes are all displaying their own clean-burning diesel solutions.
Toyota says hybrid models are the cleanest in the market
And there is plenty of scope for progress according to their Korean rival Kia, which has recently come up with a new diesel engine for its Ceed model that will deliver a 37% cut in emissions and a 44% reduction in fuel consumption when compared with its current engine.
"It is just a matter of pushing the manufacturing button," Jean-Charles Lievens, senior vice president, Kia Motors Europe, told BBC News ahead of the inauguration of the carmaker's new European headquarters and design centre in Frankfurt.
In spite of such efforts, and despite such potential, few expect the industry to be able to meet its own voluntary CO2 emissions targets by next year.
The car industry has vowed to reduce average emissions from cars in Europe to 140 gram per kilometre by 2008 as part of efforts to reduce global warming.
Last year, the average was reduced by just 0.2% to 160 gram per kilometre, thus raising concern that its progress was too slow to meet next year's goal.
Competition in hybrid technology is healthy, Toyota's boss believes
"There's not going to be a revolution [this year]," said Horst Schneider, analyst, West LB Panmure.
The European Union is considering a legally binding target for average CO2 emissions of 120 gram per kilometre by 2012, with further reductions thereafter pushing down the average to 80 gram per kilometre by 2020 - half the current average.
Rapid growth in car ownership across the world over the next decade is expected to more than wipe out any gains in the average emission level per car.