We stop looking at mechanical efficiency and seek less tangible things.

For mechanical efficiency, opposite arms usually swing with each leg while marching.

Creating a perpetual motion machine of the third kind would require 100 percent mechanical efficiency.

Both aerobic and anaerobic exercise work to increase the mechanical efficiency of the heart by increasing cardiac volume (aerobic exercise), or myocardial thickness (strength training).

Higher tension reduces slip, which increases belt life and mechanical efficiency.