What is the primary reason a higher vehicle speed significantly increases fuel consumption beyond a certain point, and how is this effect quantified by a specific aerodynamic parameter?

The primary reason a higher vehicle speed significantly increases fuel consumption beyond a certain point is the dramatic increase in air resistance, also known as aerodynamic drag. Air resistance is a force that opposes the motion of an object through the air. As a vehicle moves, it has to push the air out of the way, and this requires energy. The faster the vehicle goes, the more vigorously it has to push the air, and therefore the greater the force of air resistance becomes. This increased force requires the e....