MOST NEW CARS CAN’T MATCH CLAIMED ECONOMY

Nine in ten new cars on sale in the UK are failing to meet their claimed economy figures, leaving millions of owners paying more than they expected to run their vehicles.

A new study comparing the economy performance quoted by manufacturers against the real-world experiences of owners has found that the gap between“official” numbers and reality is its widest point ever.

An average car now uses 24 per cent more fuel than the official figures suggest. among the worst culprits are Britain’s best-selling car – the Ford Fiesta – which achieves just 71 per cent of its claimed economy, the popular MINI hatchback (70 per cent) and the Audi A4 (68.3 per cent.

The worst offender, however, is BMW’S X5 SUV, which manages just 66.9 per cent of its official figures.

According to Honestjohn. co.uk, which carried out the study, one of the key problems is that car manufacturers have been fined if the corporate average CO2 emissions of their cars exceeds 130g/km according to laboratory tests.

To avoid these fines, vehicles are increasingly optimised for the laboratory test at the expense of real-world performance.

As a result, Honest John says, British motorists are unwittingly using an estimated 2,970 million extra litres of petrol and an additional 2,609 million litres of diesel every year.

The findings are based on 118,000 submissions to the website’s Real MPG section.

This covers all major makes and models and invites car owners to submit the actual economy their vehicles achieve during day-to-day use.

The figures released today are averages across the whole of a model range.

Honest John’s managing editor, Daniel Powell, said: “Real MPG has shown that, for the majority of drivers, advertised fuel economy figures are quite simply too good to be true.

“As a result, many are finding it increasingly difficult to understand how much fuel a car will use or how polluting it will be.”

Oliver Rowe, product affairs manager for Ford UK, pointed to the differences between the official tests and real-world driving to explain the disaparity in the Fiesta’s figures.

He said: “All Ford vehicles comply with the mandatory laboratory-based New European Driving Cycle (NEDC) approval test. Other results vary based on different conditions of temperature, humidity, aerodynamic resistance, road surface etc, all of which can increase emissions.”

From September this year, the current tests will be replaced with the Worldwide Harmonised Light Vehicles Test Procedure (WLTP).

This is claimed to be more reflective of real world driving conditions and involve longer distances and higher speeds.