You might guess that the minimum-drag speed ought naturally to be the best range speed as well, but it isn’t. The reason is that, as you increase power from the minimum required to stay aloft, speed at first increases more rapidly than fuel flow does. Just how much higher the best-range speed is than the minimum-power speed depends on airframe, engine and propeller characteristics, but it’s going to be somewhere around 40 or 50 percent above the clean stalling speed. Like most aerodynamic curves, the speed-power curve is pretty flat at the bottom, and so you might as well err on the high side and call it 50 percent, especially because “half again” is easier to calculate in your head than “four-tenths more.” An airplane with a 54-knot clean stalling speed would have a best-range speed — this is an indicated, not a true, speed — of 54 plus 27, or 81 knots, and one with an 80-knot stalling speed, 120 knots. Most single-engine airplanes have clean stalling speeds below 70 knots, and so the best-range speed of the faster ones would be around 100 to 105 knots.