nicklockard
Torque Dorque
Well, it's all been done before, with technology that is 30 years old -or older.
Ford probe 5 , with it's .137cd
http://www.christies.com/LotFinder/LotDetailsPrintable.aspx?intObjectID=3942143-
TDI engine made/sold by Elsbett (that already gets around 100mpg in a Mercedes chasis) http://en.wikipedia.org/wiki/Elsbett
Hydraulic regenerative braking system (90% efficient vs electric @40%) http://www.hybridcars.com/related-technologies/hydraulic-hybrids.html
Easy- peasy to hit 150mpg! Plus it looks sexy, and seats 4-5 adults.
The Elsbett engine is intriguing, though I can hardly find much actual use or sale of it in the 'net.