Abstract: The disclosure comprises a pair of inflatable substantially inelastic lobes. A single lobe can be mounted on each of the rear trailer doors of a standard tractor-trailer unit. Each lobe can be inflated or deployed to provide an aerodynamic substantially planar contour extending rearwardly of the rear end of the vehicle. The aerodynamic shape of the lobes with stable and substantially planar external surfaces for air to pass over can be created by a series of internal cords and flag sets extending substantially horizontally and vertically in an array from one side of the lobe to the other side of each lobe. When the lobes are deflated, the trailer doors can be opened and latched to the side of the trailer in a conventional manner.

Abstract: The disclosure comprises a pair of inflatable substantially inelastic lobes. A single lobe can be mounted on each of the rear trailer doors of a standard tractor-trailer unit. Each lobe can be inflated or deployed to provide an aerodynamic substantially planar contour extending rearwardly of the rear end of the vehicle. The aerodynamic shape of the lobes with stable and substantially planar external surfaces for air to pass over can be created by a series of internal cords and flag sets extending substantially horizontally and vertically in an array from one side of the lobe to the other side of each lobe. When the lobes are deflated, the trailer doors can be opened and latched to the side of the trailer in a conventional manner.

Abstract: The disclosure comprises a pair of inflatable substantially inelastic lobes. A single lobe can be mounted on each of the rear trailer doors of a standard tractor-trailer unit. Each lobe can be inflated or deployed to provide an aerodynamic substantially planar contour extending rearwardly of the rear end of the vehicle. The aerodynamic shape of the lobes with stable and substantially planar external surfaces for air to pass over can be created by a series of internal cords and flag sets extending substantially horizontally and vertically in an array from one side of the lobe to the other side of each lobe. When the lobes are deflated, the trailer doors can be opened and latched to the side of the trailer in a conventional manner.

Abstract: The disclosure comprises a pair of inflatable substantially inelastic lobes. A single lobe can be mounted on each of the rear trailer doors of a standard tractor-trailer unit. Each lobe can be inflated or deployed to provide an aerodynamic substantially planar contour extending rearwardly of the rear end of the vehicle. The aerodynamic shape of the lobes with stable and substantially planar external surfaces for air to pass over can be created by a series of internal cords and flag sets extending substantially horizontally and vertically in an array from one side of the lobe to the other side of each lobe. When the lobes are deflated, the trailer doors can be opened and latched to the side of the trailer in a conventional manner.

Abstract: Drag reducing apparatus for the rear end of a road vehicle such as a truck or trailer comprises a storage container in which an inflatable bladder is rolled on a support shaft for displacement relative to the container between a stored position and a deployed position in which the inflatable bladder covers the rear surface of the vehicle and is inflatable to provide an aerodynamic contour extending rearwardly of the vehicle. The inflatable bladder is extendable and retractable relative to the container by cables having ends attached to the container shaft and opposite ends connected to a cable shaft, whereby rotation of the latter pulls the inflatable bladder from the container and rotation of the container shaft in the opposite direction rewinds the bladder into the container for storage. Guide and support tracks and a spring clip arrangement hold the periphery of the bladder against the rear surface of the vehicle when the bladder is in its deployed position.