The Opel Flextreme is a Opel’s first electric car that will be based on the Chevy Volt will be manufactured in the U.S. The European customers should expect to pay a substantial surcharge of $15,800 or more over a comparable Opel model with a conventional diesel or gasoline powertrain. The Opel Flextreme was previewed in concept form at last Frankfurt Auto Show is due to arrive on European dealerships in 2012.

Homogenous Charge Compression Ignition (HCCI) is a technology, that combines an oil-burner’s fuel eco­nomy with the smooth, free-revving character of a petrol engine, courtesy of some clever engineering.

Standard diesels don’t use spark plugs. Instead, they compress the fuel and air mixture until it’s hot enough to burn by itself. Engines fed on unleaded, however, need a spark to get the process going.

The HCCI system redirects some of the exhaust gases back into the combustion chamber, which warms up the petrol and air mix so that it doesn’t need a spark to ignite. Up to half throttle and 3,000rpm – typical conditions for driving in traffic – the engine works in HCCI mode with huge gains in efficiency.

The rest of the time, if the driver is accelerating hard, it automatically converts back to a conventional spark ignition set-up. That results in a 15 per cent improvement in efficiency. Expect to see this engine offered in the Opel Insignia from early next year. GM has been working on HCCI technology for

Opel is planning to launch a series of electric-powered cars under Chevrolet Volt program. The recently announced $1 billion investment will include the development of various electric-powered vehicles based on the E-Flex architecture.

First up will be the production version of last year’s Flextreme Concept that is expected to arrive in the European market one year after the Chevy Volt, in 2011.

The Flextreme combines an electric propulsion motor and a 1.3-liter CDTI diesel. The diesel engine is onboard solely to power the generator and charge the battery.

The Flextreme can be charged in around three hours via a standard 220 V electrical socket. A fully charged lithium-ion battery gives the concept car a range of around 55 km or 35 miles in purely electric operating mode. When the battery is run down and no electrical socket available, the Flextreme’s common-rail diesel engine kicks in to provide electricity and recharge it.