The **air filter** is an essential part of the engine's fuel system, whose function is to clean the air entering the engine. This air can contain environmental dirt, and the filter is responsible for removing these impurities so that the engine operates correctly.

- When the **air filter is dirty**, the airflow to the engine is reduced. This can cause the engine not to receive enough clean air, affecting its performance, especially at **high revolutions per minute**.
- A dirty filter can lead to an increase in fuel consumption and, in extreme cases, can cause the engine to fail or operate inefficiently.
- It is important to check and change the air filter regularly, especially in conditions where there is a lot of dust or during the summer, to ensure that the engine receives the necessary air for its proper functioning.

Therefore, a **dirty air filter** is a common cause of engine failures at high revolutions, as it prevents the engine from receiving the necessary air for optimal operation.