A comparison of 75 new cars tested in real-world conditions by Professional Driver magazine has revealed that none match the manufacturers’ quoted combined mpg figures.
The average overstatement was 37.39%, with some cars having a quoted figure as much as 74% above the real-world test figure. Not one of the 75 cars evaluated matched or bettered the quoted figures, which are calculated in laboratory conditions using a rolling road.
The majority of the cars tested by the magazine were diesels, as these remain the most popular cars for the private hire sector. But a number of popular hybrid models were also tested, and some of these fared even worse than the diesels – the average over-statement for hybrids was 39.42%.
Editor Mark Bursa believes the results highlight the weakness of the testing process used to set benchmark figures for the car industry. “The simple rolling-road tests are simply not rigorous enough to simulate driving conditions in the real world. There are no hills or even corners on the tests, and the tests only last for a few minutes. The manufacturers are able to prepare their cars so they perform to the maximum – reducing weight and electrical features to optimise fuel economy. And the short nature of the tests favours hybrids, especially those which offer a high proportion of electric drive when driven gently.”
“There is a direct link between fuel economy and CO2 emissions, and that means all the cars we’ve tested are certainly emitting more CO2 than claimed. Some would certainly be in a higher tax band if real-world figures were used,” said Mark Bursa. “The government could be missing out on tax revenue as a result.”
Over the past few years there have been countless articles from the motoring press about the disparity between the official figures for fuel consumption and emissions and life in the real world. Perhaps now in the glare of publicity following the Volkswagen scandal, governments will take positive steps to introduce sensible testing that drivers can rely on when choosing a new vehicle.
www.prodrivermags.com
Photo: Real-world fuel consumption figures were all lower than those quoted by manufacturers in the test.
David Jordan, Deputy Editor of The Mover, recently bought a new car advertised as doing 43.5mpg that, despite being driven very carefully, has yet to achieve more than 33mpg. It’s not right is it!