TOKYO - Oil is getting scarce and the internal combustion engine adds to pollution, therefore the car of the not too distant future needs a new motor. But what?

Delegates at the Nikkei automotive conference here, in the week of the Tokyo Autoshow, reviewed the industry's sputtering progress towards new power systems in the knowledge that if they do not come up with a solution the sector may come to a halt. "In the long-term, it's very clear that on-road transportation has to decouple from petroleum for both dependency and greenhouse gas emissions reasons, and the pathway for that is electric drive," Michael Milikin, editor of the Green Car Congress publication, told Reuters.

There are various propulsion technologies under study but none is without its disadvantages. Hybrids reduce fuel consumption but still use fossil fuel; hydrogen is clean in a car but takes a lot of energy to produce; solar needs sunshine and plenty of surface area; and fuel cells are as yet too big and too expensive to make.

French engineer Guy Negre has developed a compressed-air engine, which has attracted interest from India's Tata Motors Ltd, but the technology is still in its early stages. Minoru Shinohara, a senior vice president at Nissan, said the Japanese carmaker believed that over the next 15-20 years, the main changes in engines and emission control would come from further developments on existing engine and transmission systems. "In the long term, there is no doubt that batteries will play a big role," he told the conference.

Daniel Vieau, chief executive of U.S.-based A123 systems, said his company was working with nano-technology to yield lighter batteries with a longer life and better power output. The main reason carmakers were not yet using batteries more is because they are too expensive, too heavy and run out too fast. At Japan's Sanyo Electric, board member Mitsuru Homma said battery performance needed to be boosted and costs cut before more hybrids and full electric vehicles hit the market.

Cost-benefit
While engineers and academics work on mould-breaking solutions that can save the globe, industrialists are more down to earth and take a cost-and-benefit approach. For them, there is no single solution on the horizon, but at least there is a road map. At the moment, hybrid engines and other fuel saving technologies are within reach. Partly spurred by CO2 emission rules or measures in the European Union, Japan and California, the addition of an electric motor to a fuel engine helps reduce fuel consumption and emissions. Toyota's Prius is an example of such a car.

Skeptics, however, such as former PSA Peugeot Citroen chief Martin Folz, often say that even with a hybrid added, petrol engines do not match the performance of diesel. While popular in Western Europe, diesel is considered truck fuel at best in the United States and is even less popular in Japan.

Car parts suppliers such as Valeo or Robert Bosch GmbH have 'start and stop' or 'stop and go' technologies where an engine is shut down when the car is stationary and resumes the moment the accelerator is touched. Other engines which do away with camshafts could cut fuel consumption by up to a fifth, and first products could be on the market by 2010.

Biofuels are already widely used in Brazil and are hitting European markets as well. Based on colza or sugar cane or other biomatter, these fuels can be mixed with diesel to cut costs and emissions. But biofuels are condemned to remain a niche application because of all the arable land needed to fuel a big proportion of the world's car fleets, land which would otherwise be used for food and other agricultural production.

(By Marcel Michelson, Reuters, 22/10/2007)