Filters are critical components used throughout vehicle systems to remove contaminants from fluids and air. Oil filters maintain cleanliness of lubricating oil, preventing engine wear; fuel filters protect injectors and engines from debris in gasoline or diesel. Air filters ensure clean airflow to the engine for optimal combustion, while cabin air filters provide occupants with breathable air by removing particulates and odors. Filter media commonly utilizes pleated paper, synthetic fibers, or nanofiber technology to maximize surface area and capture efficiency, with construction varying based on application and contaminant type. Key specifications include micron rating, flow rate capacity, and physical dimensions for proper system integration.