Sean, yes there will be less pumping loss at WOT. But you're confusing volumetric efficiency with fuel consumption. Obviously gunning the motor is not the best way to save money at the pump. If your Cobra made 30hp, then this would work... or if it were a diesel.
With a motor that makes enough power, with more throttle the computer will increase pulse width to prevent the motor from going crazy lean, right?
And what you said about wind resistance is true, yes. The power required to propel the vehicle increases at the cube of the speed while aerodynamic resistance increases at the square. Which is why I specified that this is assuming the engine produces enough power to pull the highest vacuum in OD. And once again, vacuum readings will take this into account.
Not trying to argue with you Sean, I know you're right. Most vehicles will do best at 55mph. This is why I avoided the words best mpg and added so many conditions. Just trying to observe the highest vacuum pulled at the lowest speeds in top gear for different vehicles, assuming my theory is correct (which can neither be confirmed nor denied).
