Chevrolet has begun testing the second-generation Volt electric car.

The second generation Volt is expected to go on sale in international markets within the next two years with production getting under way at GM's Detroit-Hamtramck assembly plant next summer.

A second-generation Vauxhall Ampera could be spawned from the new car, as well as a new Cadillac ELR, but with the current Ampera only three years old a Vauxhall spokesman told our sister-magazine Autocar UK, the brand is "fully committed to the Ampera in its current guise" in the UK.

However, rumours persist that the new Volt's drivetrain could be used by Opel in a more European-friendly car. Opel has reportedly told its German dealers the new model will arrive in either in 2016 or 2017 and will be smaller and more affordable than the current Ampera, and is currently code-named 'BEV'.

Likely to sit on the same platform as the next-generation Chevrolet Cruze, the new Volt features different styling to the current car, adopting a less box-like design at the rear with new tail-light clusters and a more rounded rear bumper. At the front, a new grille features on the redesigned front bumper, which also includes new lower air intakes and vertical LED DRL units. Swept-back headlight clusters can also be seen, alongside new wing mirrors and a steeper windscreen.

The current Volt can manage up to 80.46km running on electric power alone, before its 150bhp 1.4-litre petrol engine starts up to act as a generator. A similar powertrain is likely to feature on the new car.

Previous reports have also suggested GM is working on an entry-level version of the Volt to sit alongside the standard car. This model would have a driving range of around 611km. This model will be priced to undercut rivals such as the Toyota Prius and Honda Accord plug-in hybrid.

GM hopes the new Volt will help to revitalise hybrid sales in the US. Sales of the Volt dropped by two per cent in the US last year to 23,094, despite continued discounts offered by dealers. In the final three months of the year, the car's sales dropped by 15 per cent to just 3,606 units.

Read our Chevrolet Volt review