I have one of these cars. We ordered it last October and picked it up in January. We have put nearly 14k miles on it those 6+ months. Its lifetime fuel economy is approximately 42.5, with the best tank coming in right at 49. It costs less than 9 cents per mile to operate (fuel only). Being lighter on the skinny pedal would bring up the MPGs, I'm sure, but I can't say that I have the patience for that...
I could not drive the car slow enough for long enough to average 77mpg. It would be painful. I am currently 1k miles away from home. The car averaged 43mpg at 80mph for the trip down.
We are happy with the car. It is my wife's daily driver and our trip car. It eats up miles, is comfortable, and so far - reliable. For a car this size
I wouldn't have bought a Passat if it weren't for the TDI.