GM: Low US petrol costs have discouraged efforts to cut consumption and led GM to scrap its most efficient models, the Chevrolet Metro and Chevrolet Prizm. The world's biggest carmaker was an ecological pioneer in the 1990s with its EV1, the world's first mass-produced electric car. It flopped, costing it over €1 billion.
GM spends over €1 billion annually on fuel-cell technology, partly in joint ventures, but doesn't expect many fuel-cell cars to reach highways before 2010. It aims to bring out a hybrid electric-petrol pick-up truck on the US market in 2004, which will cut consumption by 10 to 15 per cent.
FORD: The Fiesta in Europe, with a direct injection engine developed with Peugeot, gets 27 kms from a litre of diesel out of town, putting it in the top flight of fuel-efficient carmakers. But cost-cutting aimed at ending hefty losses has prompted Ford chairman Bill Ford Jr to say that further efforts to cut greenhouse emissions "will be tempered by near-term business realities."
Ford is closing its Th!nk Norwegian electric car venture, in which it had invested over €100 million, due to disappointing sales. It has brought out several fuel-cell concepts in the past two years and is working with Ballard Power Systems on more. A hybrid of its Escape compact SUV is due next year.
TOYOTA: The leader in environmentally-friendly car technology, Toyota's Prius hybrid, which went on sale in 1997, travels 31 kilometres per litre, making it possibly the world's most efficient five-seat car.
Toyota and Honda are racing to put a fuel-cell passenger car on the market by year's end, though only a few would be sold, on a lease basis, to government bodies, research institutions and energy companies. Toyota doesn't expect full commercialisation of fuel-cell cars until 2010.
RENAULT: It's most fuel-efficient car is the Clio 1.5-litre DCi, which can travel 23.8 kilometres on one litre. A hybrid and pure electric versions of its Kangoo minivan will go on sale in October.
In 2000, Renault and Nissan launched an €800-million joint fuel-cell programme. Nissan has brought forward its goal of selling fuel-cell cars to 2003 from 2005. Renault says it hopes to industrialise them in 2010.
Nissan lost face recently when it asked Toyota to supply it with hybrid systems for at least 10 years for an undisclosed fee.
DAIMLER CHRYSLER: It's most efficient car is the Smart CDI, which travels 29.4 kms on a litre. The Smart is still not available in Ireland. The company estimates it will have spent €1 billion in the 14 years to 2004 on fuel-cell technology. It has produced five New Electric Cars (Necars) since 1994 using various technologies. Its Chrysler arm has developed a "Natrium" fuel-cell car which stores hydrogen as sodium borohydride, a non-toxic solution similar to soap.
The company will produce a limited number of fuel-cell buses from next year and wants to be selling cars using the technology from 2004, but company officials expect traditional engines to be with us for another 30 years.
VOLKSWAGEN: A pioneer in fuel-efficient direct-injection diesel engines. Its Lupo 3L can travel 33 kilometres on one litre. VW has shown a prototype bullet-shaped car which can travel 100 kms on just one litre, though it will not go into production.
A fuel-cell Bora crossed the Alps in January, but VW says fuel-cell cars probably won't hit the market for 15 to 20 years. VW is concentrating on intermediate solutions first, such as synthetic fuel and biomass.
PSA PEUGEOT CITROËN: Its cleanest mass-produced car is the Citroën C3 equipped with the same 1.4-litre diesel engine as Ford's Fiesta. The vehicle emits 110 gms of carbon dioxide per kilometre - the European industry target is a maximum 140gms by 2008.
Europe's number-two carmaker aims to be selling so-called "mini-hybrids" next year, using an electric motor to accelerate from standing in crowded town centres, cutting fuel use by between seven and 10 per cent.
In Paris, PSA will show off its latest fuel-cell ideas with the H2O, a concept spin-off of its Peugeot 206, adapted for fire brigades, which makes hydrogen chemically on board.
HONDA: Leads the race among large carmakers for fuel economy in mass produced cars. The aerodynamic Insight two-seater hybrid boasts 35 kms per litre. Also sells a hybrid version of its Civic model, which can travel 29.5 kms per litre.
Honda's fuel-cell car to be released soon will use a fuel-cell stack developed by Ballard Power Systems, though it hopes to have its own stack ready before long.
BMW: Hydrogen-powered combustion engines are, for now, more practical than electric motors powered by hydrogen fuel cells, says BMW. It has developed a prototype of its 7-Series using that technology and hopes to introduce a limited number of cars using it in five years' time.