Disclosed is a tractor-trailer including a tractor having a lower tractor duct that receives first air from a front of the tractor and channels the first air through a center area of the tractor and down between a set of rear wheels, a trailer having a lower trailer duct positioned below a cargo space and that channels the first air in the lower trailer duct between each set of trailer rear wheels and a lower articulation duct positioned near the set of rear wheels in the tractor that receives air from the lower tractor duct and communicates air to the lower trailer duct. An upper duct is also provided with an articulation duct that channels air through a ductwork at the top of the trailer and tractor. A louver system at the rear of the trailer enables the air in each duct to be channeled and pulled out of the respective duct in such a manner as to reduce drag and eddy currents using the vacuum at the rear of the trailer.