http://www.aptera.com/faqs.php Aptera FAQ's] , retrieved 12/30/2008 By mid-2008, aerodynamic optimization using simulations and light-weight composite construction yielded a prototype which allegedly consumed only 80 Wh/mi (watt hours per mile) (50 Wh/km) at 55 mph , less than half the energy needed to propel the EV1 or the Tesla.