So says the brand, adding that the typical American Volt owner who regularly charges the vehicle is going 905 miles between fill-ups of the gasoline engine that powers the Volt's on-board generator. That avoids about $1,300 (£855) at the pump.

The Volt has a published Environmental Protection Agency-estimated mileage of 98 MPGe petrol-free miles, which is the agency’s way of comparing the consumption of alternatively fuelled vehicles with conventional internal combustion vehicles expressed as miles per US gallon of petrol.

Some drivers are almost managing to avoid filling up altogether.

‘I have driven more than 23,500 miles in my Volt in 21 months, and have been to a gas station twice,’ said Brent Waldrep of Auburn Hills, Michigan. ‘The last time, was in August 2012, and I still have about 65% of that tank left. I go about 9,000-10,000 miles between fill-ups.’

Meanwhile Larry Read of Canyon Lake, Texas added: ‘It's been more than 5,000 miles and I've only filled up once not including the dealer fill.’

 ‘We've seen and heard from our Volt owners that they are achieving fantastic performance numbers with their vehicle as many are beating the EPA label estimates,’ said Cristi Landy, Chevrolet Volt marketing director. ‘Our Volt owners are showing the performance potential of driving electric, and having fun doing it.’

When the Volt is fully charged, the power used for driving up to 50 miles is supplied by the electricity stored in its 16 kWh lithium-ion battery. A petrol-fuelled engine kicks in and generates electricity to sustain the charge of the battery, once the battery's energy is depleted.