or has certified labs test it. Interestingly, the tests are required to use a real human driver in a controlled test cell (a dynamometer). The driver has to ke

or has certified labs test it. Interestingly, the tests are required to use a real human driver in a controlled test cell (a dynamometer). The driver has to keep the speed between two narrowly spaced lines ( a min and max - see their video) for something like 20 minutes. There is still a 3-5% fuel economy between the 'bad' and 'good' drivers or at least there was in 2003 when I toured one of these labs as an undergrad.