Reducing emissions and raising fuel efficiency are the magic words at the Frankfurt International Motor show (IAA) as manufacturers and suppliers go all out to out-do each other -- or at least out-talk each other.

Cutting greenhouse gas emissions from one of the prime suspects blamed for climate change is on everyone's mind this year -- from luxury carmakers to tyremakers, from sat-nav producers to car clubs teaching fuel-saving driving techniques.

We're stopping emissions, not emotions, BMW chief executive Norbert Reithofer told journalists. We want to show you can still have fun driving without harming the environment.

Environmentalists might dispute that, noting the gas guzzlers with up to 530 horsepower on display at this edition of the car show, and have rejected the notion that cars can be green, clean or environmentally friendly in any way.

Yet BMW and other leading carmakers did offer more than just hot air on Tuesday, the first day of the world's largest car show. BMW presented a hybrid sports activity vehicle Concept X6 (SAV) due out in 2009 that it said will slash emissions.

We've been working on this for the last five years, long before it became an issue for the media, politicians and the public, Reithofer said as BMW beat the rest of the German industry into the increasingly popular arena of hybrids -- that reduce emissions by combining combustible engines and batteries.

Reithofer said BMW's long-term goal was to make cars that would be powered without the use of fossil fuels at all.

Mercedes-Benz brand said it will begin serial production within three years of a small car powered by a zero-emissions hydrogen fuel cell.

FUEL SAVING TYRES

There was also a buzz in the vast Volkswagen exhibition hall around the new concept car model called simply Up! -- a rear-engine, three-door four-seat vehicle that sips just three 3 litres (0.7925 U.S. gallons) of fuel per 100 km (62.14 miles) -- and to be sold for less than 10,000 euros ($13,830).

Volkswagen has been working for a long time on fuel efficiency, said Volkswagen chief executive Martin Winterkorn, rejecting criticism that they and other German manufacturers had been asleep at the switch in developing low emission cars.

Also drawing a crowd of interested onlookers among the thousands of journalists was Volkswagen's new SAV -- the Tiguan, a smaller and cheaper version of its Touareg model.

General Motors' Opel unit presented an electric concept car called the Flextreme it hopes to bring out in 2010.

Opting for an electric car rather than a more expensive hybrid, Opel said the battery-powered car can hit up to 160 km/h and its lithium battery can be charged by plugging into a socket or with a small turbo diesel motor.

But it is not only the carmakers talking about climate change. Michelin presented what it called a world premiere -- its energy saver tyre that it said can save 3 litres of fuel per 1,000 km by reducing rolling resistance.

Not everyone, however, was convinced carmakers had suddenly become true believers in the fight against climate change.

Some of the carmakers have finally got the message that they have to do more to protect the environment, said Winfried Hermann, a member of parliament for the Greens party that had a stand at the IAA for the first time this year.

They put on a massive advertising campaign before the IAA about cars and the climate. But unfortunately the campaign is far ahead of the cars they're showing. These cars are nowhere near as climate-friendly as they're selling it to us.

Volkswagen