Ever stick your hand out the window at highway speed? Do it palm-first, and the air pushes your whole arm backward. Hold your hand out palm down and you can control arm movement, even against the air pressure. Tilt your hand upward, and air pressure forces your arm higher. Go the opposite way and tilt downward, and your hand gets pushed downward. You’ve just experienced the aerodynamic properties of drag, lift, and downforce. Air flowing over, under, and around a car acts the same way.
DRAG AND FRONTAL AREA
Palm-first, your hand has lots of resistance. That’s why air pressure pushed it back. Engineers call this drag. Measured in pounds, total drag is a combination of the vehicle’s frontal area, dynamic pressure (air density and velocity), and a shape factor…