Contrary to all the evidence, a lot of effort goes into the choice of model name for a new car. It should be catchy, easy to pronounce, and somehow sum up the aspirations of the potential buyers.

But now there’s a whole new strand to this delicate task. It’s the electric car.

Chevrolet has undoubtedly bagged the best name for its ground-breaking electric car - the Volt. In energy unit terms, it’s got iconic status. It brings to mind power, sparks and, if the numbers are big enough, sheer danger.

Tesla is not bad either. It’s a unit of magnetism – quite appropriate for the first electric sports car.

Vauxhall’s Volt will be called the Ampera – that’s the SI unit for electric current. Now, shall we speculate on the though process behind that…