Abstract: By providing an upstanding drag reducing baffle wherein the upper edge of said baffle comprises smoothly curved extension portions on both sides thereof, lying in substantially the same plane of the baffle, an improved wind deflector capable of increased drag reduction is achieved. In the preferred embodiment, these extension portions extend from the edge of the baffle toward the center and comprise at least half the distance from the edge to the mid-point of the baffle. Also, in the preferred embodiment, a front curved vortex stabilizer, a portion of which extends above the wind deflector, is used in combination with the wind deflector for additional drag reduction.

Abstract: A drag reducer for a gap in a land vehicle moving through air capable of stabilizing the stagnant air in the gap which tends to rotate and form a horseshoe shaped vortex. The vortex directs the surrounding airstream around the stable vortex and thereby reduces air resistance. The drag reducer is a substantially V-shaped plate having concave sides vertically mounted midway in the gap existing between a tractor and trailer on the forward panel of the trailer. The plate stabilizes the rotating vortices and, particularly, prevents side winds from forcing the vortices out of the gap. The drag reducer can take the form of two plates mounted in parallel on one wall or can be mounted on opposite walls substantially in the same plane.