New study finds European cars aren't as efficient as stated

Cheating on fuel economy ratings is apparently not limited to the United States market as a new study has discovered that European automakers inflate their stated fuel economy data by about 25 percent compared to “real-world” driving.

A new study conducted by the non-profit group International Council on Clean Transportation (ICCT) found that European cars average about 25 percent higher "real-world" carbon emissions based on fuel consumption than stated on their window stickers. That compares to a 10 percent variance just 10 years ago.

ICCT found the worst offenders to be Germany luxury car makers. According to the study, BMW's vehicles spew about 30 percent more carbon emissions than stated by the automaker during real-world driving. Audi wasn't far behind with a 28 percent disparity, followed by Mercedes-Benz with a 26 percent difference.

On the lower end of the study, Toyota missed its stated emissions by 15 percent while PSA Peugeot Citroen's figures were about 16 percent below what drivers in the real-world would experience.

"This means that the actual fuel consumption experienced by the average driver is typically 25 percent higher than what is printed on the sales sticker," Peter Mock, managing director of ICCT Europe, told Reuters.

That discrepancy could cost drivers about $400 in extra fuel costs per year.

Here in the United States, Hyundai and Kia were busted in late 2012 for inflating their vehicles' stated mileage. Ford has also come under scrutiny for its mileage claims, although the automaker has never admitted to any wrongdoing.