Vehicle air filters are an essential component of a car's engine system. They work by preventing harmful debris, dust, and dirt particles from entering the engine. The air filter is usually located in the engine bay and is made up of a paper or foam filter element that traps the contaminants and prevents them from reaching the engine. 

The air filter's primary function is to ensure that the engine receives clean air for combustion, which is essential for optimal engine performance. A dirty or clogged air filter can cause a reduction in engine power, decreased fuel efficiency, and even engine damage over time.

Vehicle air filters come in different shapes and sizes to fit different types of cars. Some air filters are reusable, while others are disposable and need to be replaced regularly. It's recommended to check and change your car's air filter periodically, usually every 12,000 to 15,000 miles, or as recommended by the car manufacturer.

In summary, vehicle air filters play a critical role in keeping your car's engine running smoothly by preventing harmful debris from entering the engine. Regular maintenance of the air filter is necessary to ensure optimal engine performance and fuel efficiency.