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(Adding short description: "Fuel efficiency of an engine design with respect to thrust output" (Shortdesc helper)) 
m (link energy consumption) 

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The following table gives the efficiency for several engines when running at 80% throttle, which is approximately what is used in cruising, giving a minimum SFC. The efficiency is the amount of power propelling the plane divided by the rate of [[energy consumption]]. Since the power equals thrust times speed, the efficiency is given by
:<math>\eta=V/(SFC\times h)</math>
where V is speed and h is the energy content per unit mass of fuel (probably the [[lower heating value]] is used here).
