FAA requires he tether it to the ground when he fires it up. 20 mpg is attractive, but it's going nowhere.
M400X Skycar
Passengers 4
Vertical takeoff and landing Yes
Emergency parachutes Yes
Fuel type Ethanol
Noise level at 500 ft (Goal) 65 dba
Dimensions (L x X x H) 19.5’ x 8.5’ x 7.5’ 5.9 x 2.6 x 2.3 m
Operational ceiling 36,000 ft 10973 m
Takeoff and landing area 35 ft dia 10.7 m
Max speed @ 25,000’ (7620 m) 330 mph 531 km/h
Max speed @ S.L. 360 mph 579 km/h
Cruise speed @ 25,000’ (7620 m) 305 mph 491 km/h
Rate of climb @ S.L. 4,800 fpm 1463 M/min
Max range (Gasoline equiv.) 750 miles 1207 km
Max mileage >20 mpg >11.76 L/100 km
Max net payload 750 lbs 340 kg
Gross weight 2,400 lbs 1088 kg
Nominal Power (continuous) 720 hp 537 kW
Boost power avail. 1,155 hp 861 kW
Disc loading 140 lb/ft2 684 kg/m2
Maximum L/D 12.5 12.5
http://www.moller.com/