The relative ranking of the cars looks right but the numbers all look low. For example, I don't have any problems get at least 50 mpg in my Prius C in almost all circumstances. On one lucky round trip I managed to hit 70 mpg. That is not the norm though. It was late at night with few cars on the road. I was under the speed limit the whole way. The stop was short, so the battery still had good charge when I left (seems like it always loses a bunch of charge while I at work). It was also a slight incline, so I was able to ride the whole way back on electric.
^^ You can read about their tests on the last page of http://www.consumersunion.org/Oct_CR_Fuel_Economy.pdf. They intentionally don't do anything to drive any of their cars in a special way or for better mileage. Google Earth can give you an elevation profile of a route between 2 points! | PriusChat can help too w/elevation change.
Not saying they should go strait to hypermiling but... I don't think that is entirely fair as different cars need to be driven different to get their optimal mileage. Driving them all the same gives an unfair advantage to the cars that just happen to get closer to optimal mpg under their arbitrary driving style. They should just try to drive the cars optimally as much as would normally be reasonable. From their results, it almost seems like they are trying to get bad mileage.
^^^ The point is to have a test that's the same across all cars so that you can compare results. I'd wager that their test is produces pretty repeatable results, but likely not as repeatable as the EPA tests (which are done on a dyno, see Car and Driver: The Truth About EPA City / Highway MPG Estimates | PriusChat). How many Prius family owners are not on Priuschat or places cleanmpg? How many of them know how to hypermile or even know the most basic (and proper) techniques to get better mileage? Extend this to the rest of the vehicles out there? I know MANY people who can't even be bothered to measure the mileage. Many cars have no trip computers or anything that displays instantaneous mpg or any sort of feedback. (Heck, my mom has an 07 NAH and she can't bothered to even measure her mileage manually. The car has a trip computer and also has a bar graph that moves left/right to give you iMPG feedback. I've taught her how to operate those and how to reset the computer many times and she still hasn't learned and doesn't seem to care.)
