>
>The HP requirements for non-accelerating vehicle on a flat road due
>to simple aerodynamic loss is shown by this formula:
>
>HP = (C * A * V**3)/146625   Where:
>         C=Drag coefficient.  An average car is around 0.35, but we will
>                 use 0.50 for these calculations.
>         A=Car Frontal Area.  I have an old 1971 Chevy Impala and it
>                 measures out to approximately 30 sq.Ft.  We will use that
>                 number.
>         V=Velocity in MPH.
>
>Thus, for 75mph; HP = (0.50 * 30 * 75**3)/146625 = 43HP
>For 60mph, HP = (0.50 * 30 * 60**3)/146625 = 22HP
>For 55mph, HP = (0.50 * 30 * 55**3)/146625 = 17HP
>
>Of course that is not considering wheel losses or hills, but you can
>see that the HP requirements for non-accelerating loads are
>significantly smaller than you might think. It is very important to
>note that the weight of the vehicle is NOT a factor in this formula.

-- BillDube@killacycle.com