Despite their ‘green’ image, electric cars are often less efficient and more polluting than the petrol cars they replace, according to a major report released today.The 168-page report, titled The Emperor’s New Car, is described as a ‘long-overdue reality check’ by its author, car expert Clive Matthew-Wilson. The report was prepared in consultation with several internationally-recognised energy experts.Matthew-Wilson, who edits the car buyers’ Dog & Lemon Guide, says: