What is the likely effect of carbon buildup on intake valves?

Carbon buildup on intake valves can lead to reduced fuel efficiency for several reasons. When carbon deposits accumulate on the intake valves, they can hinder airflow into the combustion chamber. This obstruction alters the air-fuel mixture that is essential for optimal combustion. As a result, the engine may have to work harder to maintain its performance, leading to less efficient fuel usage.

Additionally, the presence of carbon can affect the timing and completeness of fuel combustion. Poor combustion can result in a loss of power and further decreases in fuel efficiency. Engines are designed to operate with a specific air-fuel ratio; when carbon buildup alters that ratio, it can contribute to incomplete combustion, which not only wastes fuel but can also lead to increased emissions and potential engine knock.

In contrast, options that suggest improved performance or increased horsepower do not account for the negative impact that carbon buildup has on airflow and combustion efficiency. Similarly, stating that there is no significant impact overlooks the substantial effects that carbon deposits can have on engine operation, including reduced fuel efficiency, which is a common consequence.