A study conducted by Transport & Environment (T&E) says Mercedes-Benz is the biggest cheater in the European fuel economy test.

A study conducted by Transport & Environment (T&E) says Mercedes-Benz is the biggest cheater in the European fuel economy test.

Mercedes-Benz takes top spot in a study from Transport & Environment regarding the discrepancies between the official fuel economy figures provided by the automaker and the actual mileage in real life conditions. They say a three-pointed star vehicle consumes 40 percent more fuel compared to what it's written in the brochure, well over the 31 percent average across all automakers. The gap has broadened over the years as back in 2001 the differences stood at just 8 percent on average.

For the typical European driver, the extra fuel consumed costs €500 each year and it's all because not only is the test obsolete but automakers have some "techniques" to improve fuel economy numbers. According to the "2013 edition of Mind the Gap!", some of the most relevant examples include overinflating the tires, using special super-lubricants, taping over cracks and around doors & grilles, minimizing the car's weight, modifying brakes & wheel alignment and testing at higher altitudes on slick test tracks during hot days.

Interestingly, the report says "modern engine management systems are even able to detect when a test is being carried out to deliver better fuel-efficiency results - a technique known as "cycle beating" that was first used to cheat tests for air pollution."

The good news is that hopefully in 2017 a new global (and more realistic) test called "Worldwide harmonized Light vehicles Test Procedure" will be implemented. However, the date is not set in stone because automakers are trying postpone its introduction until at least 2022.

Be part of something big

Study finds Mercedes-Benz biggest cheater in Europe's fuel economy test