Chevrolet Volt nabs 230mpg rating

This makes the Volt the first car ever to receive a triple digit fuel economy rating, although this figure may not be as impressive as it sounds.

When calculating the efficiency of extended-range vehicles, the US Environmental Protection Agency had to develop a new methodology to consider the unique drivetrain arrangement of the Volt.

GM Holden plans to introduce the Volt into Australia in 2012 and will market it as the Holden Volt.

The official figure is based on combined electric only driving as well as the Volt's charged sustaining mode with the engine running, calculated on the urban cycle.

To put this figure into perspective, the Volt's lithium-ion batteries are capable of powering the car for around 40 miles or 65km.

The Volt's small petrol engine kicks in when power levels are low, generating electricity which in turn powers the wheels for longer drives.

In this driving mode, the Volt uses around 4.7-litres per 100km, or about the same as a small diesel-powered car.

However by this stage the Volt has already travelled at least 65km using no fuel at all - so over a 100km trip, a distance of only 35km would have been covered with the petrol engine running.

Still confused? Well the bottom line is that if you keep your trips to below 100km between charges you can achieve the fabled triple digit fuel economy rating.

This latest announcement certainly represents a beacon of hope for GM which was perched on the brink of collapse just a few short months ago.