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Mercedes Models Emit 50% More Than Claimed, NGO Asks for Gas Engine Defeat Device Probe

A new study compiled by NGO Transport & Environment (T&E) has found cars made by BMW, Mercedes and Peugeot consume about 40% more fuel than officially claimed. What's more, in the case of the A-, C- and E-Class, CO2 emissions were more than 50% higher in the real world than in German laboratories.
Mind the Gap 2015 1 photo
“The gap between official and real-world performance found in many car models has grown so wide that it cannot be explained through known factors including test manipulations. While this does not constitute proof of ‘defeat devices’ being used to fiddle fuel economy tests, similar to that used by Volkswagen, EU governments must extend probes into defeat devices to CO2 tests and petrol cars too,” says T&E in their press statement.

We've suspected all along that petrol engines also have defeat devices and that the other companies that sell diesels in the US have developed them (BMW, Mercedes or GM). Mercedes have denied using the so-called "defeat device" system that lies at the core of the Volkswagen Dieselgate scandal. However, officials have hinted they will stop development of diesel engines in favor of hybrids.

The fact that there's a gap between real world fuel consumption and official numbers is hardly a surprise. For years, we've been saying that some consumption figures could not be achieved during our tests, even with zero traffic. There's no such thing as engineering alchemy, so by making vehicles heavier and more powerful, automakers are also increasing their thirst for fuel.

Data compiled by T&E revealed the gap has been increasing since 2001 and accelerated in the last 3 years: "The gap between official test results for CO2 emissions/fuel economy and real-world performance has increased to 40% on average in 2014 from 8% in 2001."

While it seemed automakers were all developing much better engines in recent years, they were actually exploiting loopholes in the system. By 2012, the gap had risen to 31% and if nothing is done it will exceed 50%.

“On average, two-thirds of the claimed gains in CO2 emissions and fuel consumption since 2008 have been delivered through manipulating tests with only 13.3 g/km of real progress on the roads set against 22.2 g/km of ‘hot air’," the Mind the Gap report says.

While Mercedes-Benz models fared the worst, the BMW 5 Series and Peugeot 308 were just below 50%, followed by the Renault Megane and VW Golf.

But it's not just Volkswagen and other automakers that stand to suffer. Every year, a typical motorist spends €450 more on fuel compared to what carmakers claim. Notice how this story has nothing to do with TDIs or nitrous oxide? Yeah, emissions tests are turning into a major scandal.

 Download: Mind the Gap 2015 (PDF)


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