For endurance, you want minimum fuel flow. For range, you want to maximise speed/drag or minimise drag/speed. For a jet this occurs at 1.316 * Vmd.
thanks WF. I would like to point out that this "fourth route of 3" factor of approximately 1.316 only applies to operations where compressibility is not a factor (generally not true for high altitude ops), and where an engines TSFC is flat with respect to speed (generally close for high altitude ops).
consider the case of a typical aircraft at FL 370, where max range is .82 for this case. divide by 1.316 gives max endurance of .62
Now does that figure make sense?
Hawk