Aircraft Fuel Efficiency

Fuel efficiency: grams of fuel per passenger per km

Aircraft fuel efficiency is usually quoted as L/100 km/pax or grams of fuel per passenger-kilometre, which is the same metric we apply to cars. Among modern wide-bodies the Boeing 787 sits around 2.9 L/100 km/pax, roughly 60% better than a 1970s Boeing 747, while the Airbus A380 comes in near 3.3. Light general aviation is far thirstier per head: a Cessna 172 is about 13. For a road comparison, a Tesla Model 3 draws around 16 kWh/100 km split across whoever's aboard. ICAO CORSIA (with its 2019 baseline) makes airlines offset whatever they emit above that line, and SAF (Sustainable Aviation Fuel) can shave life-cycle emissions by up to 80%. To put numbers on it: 2500 L of jet-A1 carrying 180 passengers over 1000 km works out to about 1.4 L/100 km/pax, a typical narrow-body figure.

Applications

Operational planning, cutting a carbon footprint, aviation ESG and sustainability reporting, comparing air against rail and road, deciding when to renew a fleet, working out route economics, hedging fuel, and keeping CORSIA offset accounting straight.

FAQ

Is flying always worse than driving? Not necessarily. On a packed long-haul wide-body the per-passenger figure can match or beat a car carrying just the driver. Fill that car with people, though, and the road usually wins again.

Why are short flights less efficient? Take-off and climb eat a disproportionate amount of fuel. On a short leg there isn't enough cruise time to spread that cost over, so the per-km consumption climbs.

Does SAF really cut emissions? Over the full life cycle, SAF made from waste or e-fuels can take CO₂ down 60–80% compared with fossil jet-A1. The catch is supply: it still covers under 1% of global demand.