This is not good, but it is much different from the NOx cheat because consumers can easily measure MPG themselves, and do. For that matter it's commonly noted i

This is not good, but it is much different from the NOx cheat because consumers can easily measure MPG themselves, and do. For that matter it's commonly noted in car magazines that U.S. EPA MPG ratings are lower the E.U. ratings for the same car & drivetrain; I'm not sure the 50% number in the OP would be so high relative to U.S. tests. It also speaks to the responsibility of the auto press for the NOx issue. They routinely report real-world MPG ratings for cars ("in our driving, we got __ MPG"), but haven't bothered to test real-world emissions despite all the other expensive gear they use to test car performance. Manufacturers and governments should be accurate and honest, but it's also the press that should be routinely verifying their accuracy. Example of skepticism at the "extremely optimistic European cycle": http://www.caranddriver.com/reviews/2017-audi-a4-prototype-drive-review#eztoc8555383_0_2 http://www.caranddriver.com/reviews/2017-audi-a4-prototype-d...