Page "Thrust" Paragraph 34

This shows why one cannot compare the rated power of a piston engine with the propulsive power of a jet engine – these are different quantities ( even if the name " power " is the same ).

There isn't any useful power measurement in a jet engine that compares directly to a piston engine rated power.

However, instead of comparing engine performance, the gross aircraft performance as complete systems can be compared using first principle definitions of power, force and work with the requisite considerations of constantly changing effects like drag and the mass ( of the fuel ) in both systems.

There is of course an implicit relationship between thrust and their engines.

Thrust specific fuel consumption is a useful measure for comparing engines.