[UFO]

Originally Posted by NeilBlanchard

2009 VW TDI has 41MPG Combined EPA rating.

2009 Jetta TDI's Mediocre EPA Rating Not Whole Story

41MPG x 0.9 = 36.9MPGe

Where's the advantage of 42% vs 25% efficiency?

The Jetta TDI is rated 30/42, the equivalent gasser is rated 23/30. There is your advantage.