The only real way to calculate heavy truck fuel consumtion is that liters/ton/100km. If you add one tonn more cargo fuel consumtion rises on 0.8 - 0.9 liter/100km.
Here is new article on mercedes benz aerodynamic truck.
Aero trailer design study from Mercedes-Benz: drastically cutting wind resistance and fuel consumption of semitrailer tractors | Daimler Global Media Site > Daimler Trucks > Mercedes-Benz CVs > Special Topics > Concept Vehicles
Biggest suprise is that there is nothing new on MB truck. Don`t they have any engineers there who can think out of the box? If so they should call me
.