On Sat, 19 Nov 2005 10:12:21 -0600 tom savage <[EMAIL PROTECTED]> wrote:
> Kevin wrote: > > Someone please correct me (I left engineering and went into econ for a > reason), but I believe that aerodynamic drag increases with the square > of velocity, while the power needed to overcome that drag increases with > the cube of velocity. It depends on the velocity regime, but, basically, yes. > So with a too-tall fifth gear, the drag overwhelms the engine's ability > to put the power to the ground sooner than it might in a lower gear. > Or something like that. Yeah, something like that. You have to consider that torque and horsepower are RPM dependent, with max horsepower toward the engine's redline. Running the engine slower in fifth means it can produce less horsepower at that slower RPM. So, depending upon exactly what the gear ratios are, it's not suprising that there are cases where the car cannot go as fast in fifth as it can in fourth. Craig
