After remarking on how boring jet engines are, the page gets vague and states that the turbofan increases "fuel efficiency", without explaining why or how. I've

After remarking on how boring jet engines are, the page gets vague and states that the turbofan increases "fuel efficiency", without explaining why or how. I've seen it assumed elsewhere that the efficiency of turbofans is due to thermodynamic effects. In this case, what the author wrote is vague about the mechanics of it, at best. In fact, turbofans have better propulsive efficiency because they accelerate more air to a lower speed. Fuel efficiency follows from that. https://en.wikipedia.org/wiki/Propulsive_efficiency#Jet_engines https://en.wikipedia.org/wiki/Propulsive_efficiency#Jet_engi...