Fuel Efficiency Posted on 11th November 20151st September 2020 by ThePD (The Project Definition) Fuel Efficiency is the ratio of heat produced by a fuel which is converted into useful work. Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on LinkedIn (Opens in new window) Related Posted in Engineering and tagged efficiency, energy. ThePD (The Project Definition) ThePD has been developing the Preferred Project Definitions based on the actual project execution and operation experiences and knowledge with the Project Language, and sharing with you daily basis.