Cadillac ELR range-extender coupe (2013) teaser image

Cadillac will launch a range-extender petrol electric coupe at the 2013 Detroit motor show in January.

This first teaser image shows the ELR will stay true to the wedgy profile of the Converj concept car of 2009.

Like its GM range-extender stablemate, the Chevrolet Volt, the Cadillac ELR twins electric drive power with a four-cylinder petrol engine, which works as an on-board power station. The car's wheels are only ever powered by electric motors, but if charge in the T-shaped lithium-ion battery pack runs low, the petrol engine fires up to juice the cells again.

The ELR was first seen at the 2009 Detroit motor show, as the Converj concept. Execs claimed the car would have a 40-mile electric-only range, and would then travel over 700 miles using internal combustion assistance. Cadillac also reported the car would develop 161bhp, 273lb ft of torque, and have a top speed of 100mph.

The ELR will go into full-scale production in late 2013, and on sale in the United States in 2014. However, Cadillac is staying tight-lipped on the possibility of European sales, or a right-hand drive version.

Cadillac has spent $35m on its Detroit-Hamtramck plant tooling the facility up for ELR production.

In total, $561m has been splashed on the Hamtramck factory since 2009. Meanwhile, the ELR's 220-cell lithium-ion battery will be built at GM’s Brownstown Battery Assembly plant in Brownstown, Michigan.

By Ollie Kew