There are many other things to consider just on engine efficiency alone, but I will not go further on that topic.
Increased engine efficiency would slightly increase, to 230 from 210, the horsepower of the 2003 model Explorer used in the study.
This reference states that a 20% to 30% increase in engine thermal efficiency is possible.
These improvements increased engine efficiency by a factor of about five, saving 75% on coal costs.
The rain that came with them would greatly reduce engine efficiency.
This results in a faster, more responsive vehicle due to greater engine efficiency.
This was done to improve engine efficiency without sacrificing reliability.
But at the moment, we're running at about 110 percent of normal engine efficiency.
The net result of his work was only a minimal increase in engine efficiency.
They sometimes reduce engine efficiency, which can lower aircraft range and/or cruise speed.