Commercial aircraft fuel efficiency is not typically expressed in miles per gallon, and for good reason. The metric used in the automotive world does not translate directly to an aircraft carrying hundreds of passengers across thousands of miles. But reframing the Boeing 767’s fuel consumption in terms familiar to most people yields numbers worth examining, both for what they reveal about the aircraft itself and for how the 767 compares to the narrowbodies and widebodies it has shared the skies with for more than four decades.

The Bureau of Transportation Statistics publishes fuel productivity data for U.S. carriers broken down by aircraft type, measured in available seat-miles per gallon. That data provides a standardized basis for putting the 767’s efficiency into context against everything from the 737 to the 787, and for understanding why an aircraft that burns over 1,600 gallons of fuel per hour can still be described as reasonably efficient.

Why Miles Per Gallon Is The Wrong Question (And Why It’s Worth Asking Anyway)

Credit: Shutterstock

Applying miles per gallon to a commercial aircraft, the way it applies to a car, does not produce a meaningful comparison. A Boeing 767 burns roughly 1,600 gallons (6,050 L) of jet fuel per hour in cruise, which across a five-hour domestic flight works out to approximately 8,000 gallons (30,300 L) for a trip of around 2,500 miles (4,020 km).

That gives the aircraft itself a fuel economy of roughly 0.3 miles per gallon, a figure that sounds absurd until you account for the fact that it is moving over 200 people simultaneously. The metric that matters in commercial aviation is fuel burned per seat per mile, or its inverse, available seat miles per gallon. This measures how far an airline can move one seat one mile on a gallon of fuel, and it is the standard basis for comparing efficiency across different aircraft types.

A 767-300ER configured with 218 seats, burning 8,000 gallons over 2,500 miles, produces approximately 68 available seat miles per gallon. Divide that figure down to a single passenger, and the aircraft delivers the equivalent of roughly 68 miles per gallon per person, which is considerably better than most cars on the road.

The per-passenger figure varies depending on how the airline configures the aircraft and how full the flight is. A 767 in a dense single-class charter layout will produce a different seat miles per gallon figure than the same aircraft configured with a premium-heavy business class cabin and 30 percent fewer seats. Load factor, the percentage of seats actually filled, further adjusts the real-world efficiency.

The 767’s Fuel Efficiency By The Numbers

Credit: Shutterstock

The Bureau of Transportation Statistics publishes fuel productivity data for U.S. carriers measured in available seat miles per gallon, which provides a standardized basis for comparing the 767 across different airlines and configurations. The 2010 data, the most detailed publicly available breakdown by aircraft type and carrier, shows meaningful variation across operators.

The 767-200ER ranged from 48.67 available seat miles per gallon at American Airlines to 60.58 at US Airways, with Continental Airlines at 53.99. The 767-300ER performed better across the board, ranging from 59.91 at United Airlines to 64.51 at American Airlines, with Delta Air Lines at 63.48. The difference between the two variants reflects the 300ER’s longer fuselage and higher seat count, spreading a similar fuel burn across more passengers. In per-passenger terms, a 767-300ER operating at typical load factors was delivering roughly 55 to 60 miles per gallon per occupied seat.

The variation between carriers on the same aircraft type comes down to configuration and utilization. US Airways configured its 767-200ERs with more seats in a denser layout than American Airlines did, which explains the 12-point gap between them on the same variant. Route length also plays a role. Shorter flights burn proportionally more fuel per mile because the takeoff and climb phase, which is the most fuel-intensive portion of any flight, represents a larger share of the total mission. A carrier flying its 767s predominantly on transatlantic routes will produce different seat miles per gallon figures than one using the same aircraft on domestic segments.

How The 767 Compares To Other Aircraft In The Same Era

Credit: Shutterstock

The BTS data allows a direct comparison between the 767 and the other aircraft types US legacy carriers were operating in the same period. The Boeing 757-200, which served many of the same carriers on domestic and transatlantic routes, produced between 67.28 and 74.79 available seat miles per gallon depending on the operator. The 737-800, the workhorse narrowbody of the era, ranged from 74.28 at American Airlines to 78.65 at Continental. The Airbus A320 fell between 70.49 and 74.38, and the A321 produced 76.29 at US Airways. Delta’s 757-300, configured in a high-density layout, achieved 83.53, the highest figure of any aircraft in the dataset.

The 767-300ER’s range of 59.91 to 64.51 is below all of those narrowbody types, as expected. A widebody aircraft carrying more fuel and flying longer stages will not match a narrowbody’s seat miles per gallon on direct comparison. The 767-200ER, at 48.67 to 60.58, sits lower still. The older DC-9 Super 80 series, at 50.01 to 54.13, was the only narrowbody in the dataset that performed at a comparable level to the 767-200ER, and that aircraft was already decades old at the time of measurement.

The comparison is useful but requires context. The 767 was not designed to compete with narrowbodies on per-seat efficiency over short domestic segments. It was designed to carry more passengers over longer distances, including transatlantic routes that narrowbodies of that era could not serve. Its fuel efficiency figures reflect that mission profile, and comparing them directly to a 737-800 flying two-hour domestic hops does not capture what the aircraft was actually built to do.

What Makes A Widebody Less Efficient Per Gallon But More Efficient Per Seat

Credit: Shutterstock

A 767 burns more fuel per hour than a 737 in every phase of flight. The engines are larger, the airframe is heavier, and the aerodynamic drag of a wider fuselage at cruise is higher than a narrowbody cross-section. On a per-gallon basis, the 767 will always look less efficient than a 737 or A320 flying a comparable route. That changes when the calculation shifts to per-seat or per-passenger terms, because the 767 is spreading that higher total fuel burn across more seats and, on a full flight, more paying passengers.

A 767-300ER configured with 218 seats at an 85 percent load factor is carrying 185 passengers on the fuel it burns. A 737-800 configured with 162 seats at the same load factor is moving 138. The 767 burns more fuel overall, but the fuel cost per passenger can be comparable or even lower on routes where demand exists to fill a widebody. Where the math breaks down is on routes where a 767 flies with significant numbers of empty seats. A widebody at 60 percent load factor burns the same fuel as one at 90 percent, but spreads it across far fewer passengers, and the per-seat efficiency drops accordingly.

This is part of why airlines have gradually replaced 767s with more right-sized narrowbodies on domestic routes where demand does not justify a widebody. The 767’s efficiency depends on filling the seats it carries, and on routes where a 737 or A321 can handle the passenger volume in a single departure, the narrowbody will almost always be the more efficient tool for the job.

How The 767 Stacks Up Against Modern Replacements

Credit: Shutterstock

The aircraft replacing the 767 on most of its remaining routes offers substantial efficiency improvements. The Boeing 787, designed as a direct successor to the 767 for long-haul routes, achieves roughly 20 to 25 percent better fuel efficiency per seat than the aircraft it replaces. That improvement comes from composite construction that reduces airframe weight, GEnx or Trent 1000 engines that are a full generation newer than the 767’s CF6 or PW4000 powerplants, and aerodynamic refinements including a more efficient wing design. The A330neo, powered by Rolls-Royce Trent 7000 engines, offers a comparable generational improvement over the original A330, which itself competed with the 767 on many of the same routes.

On the narrowbody side, the A321XLR is taking over thin long-haul routes that the 767 served for decades, including transatlantic segments where passenger volumes do not support a widebody departure. The A321XLR carries fewer passengers, but burns far less fuel in total, and on routes where the demand fits a 180 to 220-seat aircraft rather than a 250-seat widebody, the per-passenger economics favor the narrowbody. The combination of the 787 absorbing high-demand widebody routes and the A321XLR taking the thinner long-haul segments has made the 767’s passenger role increasingly difficult to justify.

The 767 continues to fly with several U.S. carriers, particularly on routes where fleet transition timelines have not yet caught up with the aircraft’s age. Its per-passenger fuel efficiency was competitive when it entered service in 1982 and remained reasonable for decades, but the generational gap between a 40-year-old design and its modern replacements is now large enough that the operating cost difference is difficult to absorb on any route where a newer alternative is available.