Opel drove its Ampera range-extender electric vehicle the 400 miles from Germany to the Geneva motor show to prove the effectiveness of the car's drive system.
The drivetrain which is capable of around 35 miles on plug-in electric power, but which also has a 1.4-litre petrol engine to act as an electricity generator to give the car an extra 300 miles' range is due to go on sale in America as the Chevrolet Volt later this year, and in Europe as the Opel/Vauxhall Ampera in 2011/12.
The Ampera is an Astra-sized car, but at Geneva Opel is showing the Flextreme GT/E to illustrate how the drivetrain might be used in a larger, more luxurious vehicle.
Range-extender drive system
The company insists that a range-extender drive system is the most logical way of bridging the gap between fossil-fuel cars and pure electric vehicles.
'The Ampera will be on sale in Europe in 2011 and I do not see an infrastructure to support purely electric cars being in place by then,' says Gherardo Corsini, the head of the Ampera development programme. 'This is the first product that is a solution for mainstream use but is also good for the environment.
'Electro-mobility is not something for niches. Only by making it mainstream can we prove this technology is sustainable.'
High price to pay
In time the range-extender powertrain may also filter down to Corsa-sized cars, although currently cost is the major issue. 'New technology is always costly,' says Rita Forst, Vauxhall head of engineering. It has been estimated that the Ampera could cost as much as 25,000 without some sort of subsidy or leasing system for the batteries.
However, Forst says the technology can be packaged into cars of any size, and hints that there could be more than one small car to adopt it.
'You have to remember that the EU has set an average CO2 target of 95g/km by 2020 and we can not meet this by conventional technology,' she said.
Vauxhall and Opel are unlikely to develop diesel range-extender cars, though. Forst says she 'does not see a place for them'.
Corsini added: 'A range-extender will be driven for most of the time within its most efficient range, similar to a petrol engine, while diesels are best at part load. Longer term, the technology is likely to be most complementary with fuel cells.'