Minimum drag speed (V_MD) is the speed at which induced and profile drag values are equal. It is also the speed that has the lowest total drag penalty, V_MD = minimum drag speed Therefore, this speed also represents the best lift-drag ratio (best aerodynamic efficiency). And because minimum aircraft drag requires minimum thrust (i.e., thrust = drag), and given that thrust is a product of engine power and fuel consumption is a function of engine power used, the aircraft thus has its lowest fuel consumption in terms of fuel used per hour. Hence it produces the maximum endurance flight time for a given quantity of fuel.

In this case, to minimise fuel consumption, the pilot should maintain altitude, keep the aircraft clean and reduce the speed to V_MD.