The data is collected in real-time via the Volt’s built-in OnStar telematics system and shown as a live counter Chevrolet’s website. 

This reveals that an average owner spends 65% of their time travelling with the engine turned off, driving 900 miles or a month and a half between refuelling stops.

To date, driving in electric mode has saved a total of 4.3 million gallons of petrol, equivalent to £13m ($21m) in fuel costs based on average American prices.