Aircraft fuel efficiency depends on many factors, not all of them directly controllable by operators. These include available technology, infrastructure capacity and safety, legal and environmental constraints. There are also many tradeoffs among emissions, noise and other design requirements.
On average, today’s jets are about 70 percent more efficient than those from the 1960s. Between 1990 and 2000 alone, aircraft fuel efficiency improved by some 17 percent, according to some estimates.
These higher fuel efficiencies are largely due to advanced engine designs that extract more useful energy from each drop of fuel. Engine manufacturers have developed engines with smaller, more advanced fans; improved compressors and turbines; reduced cooling flows; better seals; low-emissions combustors; and lighter-weight materials such as titanium, ceramics and composites. This has led to higher core efficiency, better propulsion efficiency, lower drag and reduced weight–all of which increase aircraft efficiency.
While engine efficiency is important, aircraft design has also played a key role in overall efficiency. Computer-aided design software has done much to help streamline new aircraft, while new materials–such as composites–have resulted in lower weights, and new manufacturing processes have yielded aerodynamically cleaner airframes.
The charts below compiled by Conklin & de Decker show the fuel efficiencies of both in-production and out-of-production business jets. All calculations are based on jet-A cost per gallon of $3.92.