This probably belongs in the QTDDTOT but fuck it...

A manual is still the most fuel effiencient gearbox you can have.
The values you see in new autos are just theoretical, because autos with 7th gear and even 10 gears will have longer gears, meaning that they CAN use less fuel on the highway, but in real life autos will just over rev the engine and the fuel consumption will be worst even if they are DCTs