GTECH/Pro Aero Drag HP Loss Calculator
This form will calculate the HP that is lost due to aerodynamic drag at a given speed.
 In order to use this form, you need to know your vehicle's drag coefficient (Cd) and frontal area.
 You can find estimated drag coefficient and frontal area values for many vehicles here.
 We cannot reply to requests for values for your specific vehicle, please search the Internet or email your manufacturer.
Cd * A * V^{3} 

HP loss due to Aerodynamic Drag is approximately equal to:   
150,000 
where:
Cd = drag Coefficient
A = frontal
area in sq. ft.
V = Velocity (speed) in MPH
This calculator illustrates how the horsepower lost to aerodynamic drag goes up by 8 times for each time the speed doubles!
For example, input a speed of 20 MPH and look at the calculated HP loss, then change the speed to 40 MPH and recalculate the HP loss  it doesn't double, it goes up by a factor of 8!