What can result from an excessively high air-to-fuel ratio in combustion?

An excessively high air-to-fuel ratio in combustion leads to a reduction in fuel efficiency. When there is too much air in the mixture compared to fuel, the combustion process becomes less effective. This results in incomplete combustion, where not all of the fuel is burned. Consequently, more fuel is required to achieve the same energy output, thus leading to wasted resources and decreased overall efficiency.

Improved combustion stability, having no effect on operation, and increased fuel quality are not applicable outcomes of an excessively high air-to-fuel ratio. In fact, while there might be some stability in combustion under certain conditions with high air ratios, it does not surpass the negative impact on efficiency. An appropriate balance in the air-to-fuel ratio is crucial for optimal combustion performance and fuel utilization.