Opel 2 seater: 113mpg at 140mph http://www.youtube.com/watch?v=mvKYUM5NkWk
1.3 Liter turbocharged Diesel, 5-speed semi-auto transmission
Pictures:
http://www.treehugger.com/files/2007/02/the-opel-eco-speedster.php
Of course, this is a GM vehicle. GM is notorious for producing project vehicles that they later crush, ie, physically demolish.
Back in the late '60's Pontiac made a two-seater version of the Firebird. It trounced the Corvette in all aspects. It was crushed.
Poster Comment:
This vehicle was run on the track shown in the video in 2005. There were comments regarding the CEO of GM that should be put out to pasture after his screwing of Chrysler; or shot.