Frankfurt  - Despite all the reports of doom and gloom in the car industry this year's Frankfurt Motor Show (IAA) was humming with optimism with manufacturers presenting a host of new ideas of how they plan to reinvent the motor car.

Clean-drive technology including lightweight materials, electric, hydrogen and hybrid drive dominated the biggest car event of the year, giving a glimpse of what our cars may look like in the coming years.

But none of the truly "green" zero-emission cars on display are ready for the showroom, prompting sharp criticism from German eco organisations such as the DHH, which called the Frankfurt show a window-dressing scam with manufacturers still placing their bets on high-performance traditional combustion engines.

"Not true," responds Matthias Wissmann, the president of the German automobile association (VDA) which organised the event. "We are the global leaders when it comes to innovative clean-drive technology".

Most manufacturers at the show indeed have plans for mass producing battery-driven microcars that will be available at "affordable prices" in the next two to three years such as the Smart ed, MINI-E and Renault BE BOP Z. E. But none of the car makers were willing to reveal in Frankfurt an actual price for their e-vehicles.

These market-ready cars have a range of between 100-150 kilometres on one electric charge, well below that of a traditional combustion engine, qualifying them mainly for use in urban centres with loading stations in close proximity.

On the other end of the spectrum BMW, Audi and Tesla showcased super sports cars with electric power that demonstrate what is technically possible if money is not an issue.

One of the show's stunners was the Audi e-tron, based on the R8 high-performance sports car, featuring four electric motors with two on each axle, producing an output of 230 kW/313 hp and a range of 248 kilometres.

In a similar vein BMW presented its Vision Efficient Dynamics concept sports car, taking design cues from the legendary M1. It is powered by a three-cylinder turbodiesel engine mated with two electric motors powered by a lithium-ion battery pack that together produce
390 hp. The plug-in hybrid has a range of 50 kilometres in full electric mode.

Mercedes is taking a parallel approach with the battery-driven Smart microcar mainly for city driving with hybrid technology for the big cars such as the S-Class and SUVs. In the long term, according to spokeswoman Eva Wiese, the company will increasingly introduce hydrogen-powered fuel cell technology.

Meanwhile niche manufacturers are offering optimised hybrids such as the Honda Insight with multi-mode drive including liquid petroleum gas (LPG) and ethanol.

The Honda Insight hybrid, selling on the European market for just under 20,000 euros (29,000 dollars), can be converted to LPG for just under 3,000 euros (4,400 dollars) with a special adapter added for using ethanol instead of petrol for the short few kilometres needed before the LPG mode automatically takes over.

In total the converted Honda Insight has a range of more than 1,400 kilometres using all three drive modes. The fuel consumption of five litres of LPG translates to a cost of just over three euros per 100 kilometres which makes it a real alternative for motorists clocking up more than 30,000 kilometres a year. (dpa)