Experience a performance upgrade with the K&N 01-09 Audi A4/RS4/S4 Drop-In Air Filter. Designed to boost horsepower and improve airflow, this high-flow, washable, and reusable air filter ensures your vehicle maintains peak performance with every drive. Its innovative design—with layered, oiled cotton media—captures contaminants while delivering a noticeable increase in acceleration and overall efficiency. The simple drop-in installation into your factory air box makes it an effortless upgrade to your vehicle’s performance.

Key Features & Benefits

• High-flow air filtration with an advanced, layered design for maximum performance
• Washable and reusable for long-term savings and consistent quality
• Backed by K&N’s 10-Year/Million Mile Limited Warranty for peace of mind
• Designed as a drop-in replacement for easy installation
• Enhanced acceleration and increased horsepower for a cleaner air intake

Technical & Compatibility Details

For optimal performance, maintenance is straightforward—clean the filter approximately every 50,000 miles on highway conditions to sustain peak airflow. This K&N air filter is specifically designed for Audi models:

Upgrade today to experience improved power and efficiency. Explore more high-performance parts in our Air Filters - Drop In collection or check out the K&N Engineering lineup for additional performance enhancements.