Bigger differences were seen with the Mini 1.6D Cooper, the Volkswagen Golf 1.6 TDI 105 Bluemotion and the Peugeot 3008 Hybrid4, which all promise to deliver between 70mpg and 75mpg, while the What Car? test figures ranged from 46mpg to 53mpg.

BBC: Fuel economy tests reveal 'true MPG'