Definition: In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.
Input: So , a fuel is more efficient if the specific impulse is higher .
Output:
The higher the specific impulse , the less propellant is needed to produce a given thrust for a given time and the more efficient the propellant is .