What effect does an improper air-fuel mixture have on engine performance?

An improper air-fuel mixture significantly decreases power and efficiency in an engine. When the mixture is too rich (too much fuel compared to air), it can lead to incomplete combustion, resulting in less power output and increased emissions. Conversely, if the mixture is too lean (too much air compared to fuel), it can cause engine knocking and damage, also leading to a loss in power. Both scenarios negatively impact the engine's overall performance, making it less efficient and reducing its ability to generate power when needed.

While some might assume that it could result in smoother operation or reduced engine noise, those conditions are generally associated with an optimal mixture. An improper mixture does not enhance fuel economy; rather, it leads to wasted fuel due to inefficient combustion. Therefore, understanding the critical balance of the air-fuel mixture is essential for maintaining optimal engine performance, power output, and efficiency.