How does the efficiency of actual heat engines compare to ideal efficiency?

The efficiency of actual heat engines is always somewhat lower than ideal efficiency because of various real-world factors that cause energy losses during the conversion of heat into work. Ideal efficiency is based on theoretical models, such as the Carnot cycle, which assumes no friction, no heat losses, and perfect thermal insulation. These models represent an upper limit on efficiency that cannot be achieved in practical applications.

In contrast, actual heat engines experience inefficiencies due to factors such as friction, heat losses to the surroundings, suboptimal thermal cycles, and limitations on the working fluid. These real-life limitations result in lower performance compared to the idealized scenarios, leading to efficiencies that never reach the theoretical maximum. Such discrepancies highlight the importance of understanding both the theoretical concepts and real-world dynamics when analyzing heat engine performance.

Other factors, such as the type of working fluid or specific design attributes of the engine, can influence efficiency, but they do not make actual efficiencies exceed ideal efficiencies. Therefore, the concept that actual heat engine efficiency is always somewhat lower than ideal efficiency accurately captures the reality of energy conversion in practical engines.