A well-known problem

Plenty of people, from European policy makers and ministers to car manufacturers and Government agencies, recognise the failings of the official test. In fact, America and Japan will both begin to use a far more demanding test next year.

Changes in Europe will take longer, though. The CARS 21 group is a high-ranking committee of transport ministers from EU countries, and it has said that the NEDC should be updated in time for the next emissions standards. Sadly, these aren't due until 2014.

The UK Government's own Vehicle Certification Agency (VCA) the body that ensures cars meet the minimum set of regulatory, technical and safety requirements, including the NEDC tests also says that the results don't have any bearing on the real world.

The VCA's own website says: 'There are infinite variations in driving styles and in road, car and weather conditions. For these reasons, the consumption achieved on the road will not necessarily match up with the official test results.'

Many manufacturers also agree that the test isn't useful. Honda, for instance, says: 'No car is likely to achieve the economy figures achieved during an NEDC test, because it is so far removed from real-world driving conditions.'