My 2000 Passat 1.8T ATW gives 33mpg on highway at 314,000 km, original engine and transmission.
Can't agree on this one. As the car and thus its mechanical/tranny ages the wear and tear accumulates resulting in sub-optimal performance compared to a new engine. As you might have noticed the older your car gets it consumes more oil.
If you have seen a Passat that is about 20 years old and still gives 35 MPG on highway let me know (I am excluding the cases where a new engine and lots of parts ave been installed).