Ford has chosen Budget Day to launch the new version of the Ford Fiesta ECOnetic. It emits just 87g CO2/km – meaning free road tax and no London Congestion Charge – with a combined fuel consumption of 85.6mpg.

If you are wondering if those claims are believable, we did an economy run in the previous Fiesta ECOnetic and managed to slightly better its official figure of 76.3 mpg, by getting 78.2 mpg in a run from Brighton to London. It took a lot of concentration and we would not want to drive like that every day, but it does suggest Fiesta MPG figures are achievable, if you are prepared to put the effort in.

Ford also commissioned independent research from environmental experts, Clean Green Cars on the CO2 performance of its models, which found that since 2006 the average CO2 emissions of its products had reduced to 134g/km today from 154.5 in 2006.

Ford points out that the three most economical versions of the Fiesta, Focus and Mondeo are now at least 20 mpg more economical than the most economical versions were in 2006. Mark Ovendon, Managing Director, said: “We cannot influence how the costs of motoring change as a result of today’s Budget, but the company is minimising their impact on Ford drivers.”