Abstract: This invention defines a low cost easily installed aerostabilizer, more commonly called a wing or spoiler, for vehicles that rises from a more horizontal than vertical orientation that it maintains at constant or accelerating speeds to a more vertical than horizontal orientation during braking of the vehicle. Power for change to the more vertical orientation is provided from either vacuum or pressure applied to a pneumatic powering device. Low cost is maintained by use of vacuum from the vehicle's engine and/or from gas pressure from the vehicle's spare tire with other sources for either vacuum or gas pressure optional. Direction of pneumatic forces is made by braking valves that preferably derive their power from the vehicle's brake system.

Abstract: Presented is a vehicle aerostabilizer(s) that is at least partially actuated by momentum forces generated on a weight when the vehicle is decelerating as when the brakes are applied. Movement of the weight translates forces to the vehicle aerostabilizer that cause the aerostabilizer to rotate to a more vertical position thereby adding aerodynamic drag forces to help slow the vehicle. Several options to doing this are offered including two or more aerostabilizers that may or may not rotate in concert. Much is dependent upon having an aerodynamically and weight balanced aerostabilizer(s) and limits on such balance are described. Damping systems to provide smooth operation and movement of the weight(s) and the aerostabilizers are also offered.