Perhaps I don't understand the measure (entirely possible!) but I think thrust-specific fuel consumption is a better indicator here. You need to account for th

Perhaps I don't understand the measure (entirely possible!) but I think thrust-specific fuel consumption is a better indicator here. You need to account for the thrust required in these behemoths: replace the gas turbine engines with piston engines large enough to produce equivalent thrust and I doubt you'll retain the fuel economy. Either way, this is an auxiliary point: the per-passenger fuel economy of airplanes is significantly higher than that of cars.