One of the most vital parts in improving efficiency in flight is improving fuel efficiency. An improvement in fuel efficiency permits a plane to travel at higher altitudes, further distances, and use more power while not consuming too much fuel. The heavier the airplane is, the higher the maximum efficiency speed is, and to achieve the true maximum range, the aircraft must slow down as fuel burns to maintain the same angle of attack and drag. The altitude a plane ascends also effects fuel efficiency. The higher the altitude a plane ascends, the less dense the air is, enabling the plane's turbine to produce less power and save fuel. An optimum altitude exists for every turbine aircraft at its given weight.

In the aviation industry, fuel efficiency is measured through specific range, which is the number of miles the airplane has traveled through air per pound of fuel consumed. Here is an example of how a specific range is determined. A business jet flying at 440 knots and burning 1,200 pounds per hour has a specific range of 0.37, which is satisfactory for a jet. Specific range calculations make it easier to compare the fuel efficiency between planes and enables engineers to develop a strategy where they can address an issue and improve fuel efficiency.