What can restricted airflow in the air intake system lead to?

Restricted airflow in the air intake system can significantly impact engine performance, particularly leading to decreased power and efficiency. An engine relies on a proper air-to-fuel ratio to maintain optimal combustion. When airflow is restricted, the engine receives less air, which can result in a richer fuel mixture. This imbalance can cause the engine to work harder to produce the same amount of power, leading to a noticeable decrease in performance and efficiency.

Additionally, inadequate airflow can hinder the engine's ability to expel exhaust gases properly, further affecting overall efficiency and can result in higher emissions. This scenario highlights the importance of a well-functioning air intake system for maintaining the vehicle’s power output and fuel economy.

By contrast, other options such as increased engine RPM, improved fuel economy, and faster acceleration times would not occur with restricted airflow, as these outcomes require an optimal airflow for engine performance.