Brussels, Belgium - We all know that it's almost impossible to match the advertised 'official' EU fuel-consumption figures publicised by manufacturers, anywhere outside a test track.
But now the 2014 Mind the Gap report - an annual analysis of real-world fuel consumption by real drivers in real cars, compared to the frankly unrealistic New European Driving Cycle figures - has shown that the gap mentioned in its title is growing.
Mind the Gap is commissioned by independent lobbying group Transport and Environment, a non-government organisation that campaigns for meaningful change in EU legislation that will actually make a difference in the amount of carbon dioxide being pumped into the sky.
And guess which European premium carmaker it names as the worst manipulator of test results?
Mercedes-Benz.
If your new Mercedes slurps 40 percent more fuel than the brochure promises, it says, it's not the fault of your heavy right foot - it's just that Mercedes-Benz is the current champion at manipulating the way cars are tested, producing official fuel-consumption figures that simply can't be matched in real-world driving.
JUST SO MUCH HOT AIR
The average gap between the carmakers' claims and real-world fuel consumption, across all car brands, has widened from eight percent in 2001 to 31 percent in 2013 for private owners and to a horrifying 43 percent for company cars.
The cost? For the typical private owner in Europe, who actually has to pay for his fuel, about €500 (R7000) extra a year.
But does that mean that the spectacular gains in fuel-efficiency advertised by new models since the current EU regulations were adopted in 2008 are just so much hot air? In a word, yes.
For instance, less than 20 percent of the improvement measured on Opel cars in the past five years has actually been delivered on the road.
Transport and Environment maintains that the current NEDC test is obsolete, unrepresentative of modern cars, and full of loopholes than that manufacturers exploit to produce better test results.
TRICKS OF THE TRADE
There are companies dedicated to optimising test results, it says, using purpose-built prototype models with specially-mapped ECU's that can detect not only when a test is being carried out, but which leg of the cycle the car is on at any given moment, and run the engine as lean as it can get away with under those specific circumstances - a technique known as 'cycle beating' that was first used to cheat tests for air pollution.
They also tape over all the panel gaps and shut lines in the body, including around the doors, bonnet, grille and boot, overinflate the tyres until they squeak, adjust the brakes so that the pads sit well back from the discs when not in use (yes, Cyril, that means you have to pump the brakes a couple of times before they will work, but who cares, there's no braking involved in the NEDC test).
They reset the camber, castor and toe-in to zero, fill the sump, gearbox and differential with super-thin, low-foaming lubricants, and reduce the weight of the test car by ditching the spare wheel, tools, floor mats and even the owner's manual!
They also test the cars at the highest permitted altitude, at the highest permitted temperature, and on super-smooth test tracks. The NEDC test allows for a maximum slope of 1.5 percent in any direction - so every NEDC test track slopes exactly 1.5 percent downhill.
A new more realistic and robust global test, the Worldwide harmonised Light vehicles Test Procedure, is scheduled to be introduced in 2017, but EU governments are delaying confirming the date, under pressure from carmakers that want to carry on exploiting the loopholes in the NEDC until at least 2022.
“DRIVERS WILL CARRY THE COST”
“The gap between real-world fuel consumption and distorted official test results has become a chasm,” said Transport and Environment clean vehicles manager Greg Archer. “Unless Europe introduces the new global test in 2017 as planned, carmakers will continue to cheat laws designed to improve fuel efficiency and emissions reductions - and drivers will carry the cost.”
Authorities in the United States have been far more effective in identifying carmakers unfairly distorting tests. Hyundai and Ford have been made to reimburse customers for incorrect fuel economy figures while Mercedes-Benz and BMW have also been recently caught and are awaiting penalties to be imposed.
Checks on production cars by the independent US Environmental Protection Agency have identified the anomalies, unlike the totally ineffective system in Europe.
“The US has shown how to provide accurate consumer information and limit the abuse of official tests by carmakers through effective market surveillance by an independent regulator,” said Archer.
“But the EU system still allows carmakers to pay testing authorities to test prototypes in their own laboratories using an obsolete test. The results are distorted fuel economy figures, more climate-changing emissions and air pollution.”