Fuelling debate

Will the new car tests also understate emissions?

NEW “real world” tests of cars being introduced in the wake of Volkswagen’s “dieselgate” scandal will wildly understate fuel consumption, it has been claimed.

The new testing regime – being launched next year and intended to rebuild trust in the industry after VW admitted cheating emissions controls – is said to be far more representative of how cars perform on the road.

However, Nick Molden, chief executive of testing company Emissions Analytics, says that while current official figures show fuel consumption to be on average 29pc higher than the true figure, the next tests will still be out by almost 15pc.

“The current New European Driving Cycle (NEDC) test is done in a laboratory and so it does not have hills to strain the engine, or the harsh braking and acceleration of the real world. It’s not representative and dieselgate blew the lid off that,” Mr Molden said.

“The new World Harmonised Light Vehicle Test Procedure ( WLTP) is better but it is still in a lab and not the real world.”

Emission Analytics has developed a testing regime which puts cars through their paces on real roads. Mr Molden claims this produces far more accurate fuel consumption figures. His system uses mobile testing rigs which fit on to cars and “sniff ” their exhaust emissions, from which fuel consumption can be calculated, as well as emissions.

After examining 800 different European vehicles over five years, Emissions Analytics has built up a database that shows or can accurately forecast the true fuel consumption of 60,000 models.

The car industry admits the NEDC needs to be replaced, having been designed for an older generation without all the extra equipment installed on modern vehicles. However, Mr Molden said car companies will still be able to modify cars for the WLTP to produce better fuel consumption figures than motorists will ever achieve.

“Manufacturers are not lying about fuel consumption. They are doing what is required to meet the test specifications,” he said. “They know exactly what the tests involve so they can optimise a car’s performance to get the best figures.”

Emissions Analytics’ test takes four hours of driving on roads in real traffic to give as accurate a representation of everyday driving as possible. The company explains the “context” of the tests but not the details, making it almost impossible for manufacturers to “game” them.

Mr Molden claimed the company’s drivers have even been followed by manufacturers to try to understand the tests so they can tweak their cars to get the best performance.

“We are not anti-manufacturer,” said Mr Molden. “The current system does not reward good performance when they should be able to shout about how fuel efficient they are under real world driving. But the bottom line is consumers are paying far more in fuel costs than they thought they would from official test figures.”

Emissions Analytics is making the results of its findings – called EQUA mpg – free to consumers on its equaindex.com website.