Cadillac Converj

Eager to prove that the technology behind the headline-grabbing Chevrolet Volt can be applied to other types of car, General Motors unveiled the Cadillac Converj concept car at the Detroit motor show.

As a result of its diversification, the Volt's propulsion system, made up of lithium ion batteries that are recharged by a small capacity petrol engine if it runs out of charge, now has its own name Voltec.

GM says the Voltec system can be used in larger or smaller cars than the Volt, but the creation of the Converj suggests that it thinks there is an initial gap in the market for a hybrid premium 2+2 coupe.

As with the Volt, the Converj has a 40-mile range on battery power alone, which GM officials say can be extended 'by hundreds of miles' by power from the engine.

The Voltec system delivers 273lbft of pulling power, 163bhp of power and has a 100mph top speed. It can be charged in three hours from a 240V socket.

Fuel saving is further enhanced by an all-glass roof incorporating solar panels and an aerodynamically efficient body shape.

The wing mirrors are also replaced by rear-facing cameras, and the wheels are sculpted to improve airflow.

The car sits on 21-inch wheels at the front and 22-inch wheels at the rear.

Insiders say that although its appearance is close to how a production model would look, albeit without some of the more outlandish details, the Converj is still several years from appearing in showrooms.