hey everyone, i just found this online...
The PAC-Car II set a new world record in fuel efficient driving during the Shell Eco-marathon in Ladoux (France) on June 26, 2005. Running on hydrogen, the PAC-Car II achieved the equivalent of 5,385 km per liter of gasoline (12,666 MPG!)
it was on the EPA's website-
http://fueleconomy.gov/feg/mostEfficient.shtml
It looks like they might be onto something.....