On Sat, 26 Apr 2008 13:58:22 +0700, Bruce in Bangkok
wrote:

You might "Ping" Roger
as to why doubling the Horse Power doesn't necessarily mean double the
speed. Has to do with all kind of hull forms and hydrodynamics and too
much of it will make your eyes cross.

Its very simple. Power required is proportional to the cube of the
speed, and, [gets out the calculator that takes no prisoners], you get
1.26 times the speed. Mileage is inversely proportional to speed. That
you can check for yourself, with your car.

Casady