Why are electric motors generally more efficient than combustion engines?

Electric motors are typically more efficient than combustion engines primarily because they can convert a high percentage of electrical energy—up to 90% or more—into mechanical energy. This high efficiency arises from the fundamental design and operation of electric motors, which utilize electromagnetic principles to generate motion. Unlike combustion engines, which inherently lose a significant portion of energy as heat during fuel combustion and mechanical movement, electric motors achieve a more direct conversion of energy.

The efficiency of electric motors is also influenced by their ability to operate at a lower temperature and their less complex thermal management needs. By minimizing energy losses, electric motors provide a greater output for the energy input, making them a more effective choice for applications where efficiency is paramount.

While having fewer moving parts contributes to the reliability and maintenance aspects of electric motors, the core reason for their efficiency advantage lies in their ability to maximize energy conversion. Thus, the answer relating to the percentage of energy converted to mechanical work accurately reflects why electric motors excel in efficiency.