Not sure how scientific this is - only 57mph and is there a tailwind? Doesn't look like he is following too close and it looks like a DSG. Claims that it achieves 50+ mpg @ 57mph w/ AC on.
http://askavwsalesguy.com/blog/2011/...assat-tdi.html
Just a thought. Also want to add that it seems the EPA is always conservative on their fuel mileage numbers for diesel powered vehicles.