K&N Cold Air Intake System: High-Flow Air-Filter, Increase Performance & Horsepower: Compatible with 1995-2001 AUDI A4; 1997-2001 AUDI A6; 1997-2001 AUDI A6 Quattro; 1996-1999 AUDI A4 Quattro, 57-0515

K&N 57i Series Induction Kits are specifically designed for each different vehicle and will free your car from the size restriction that comes with the factory air box. These economical kits can take a variety of different forms based on vehicle characteristics and available space under the hood. Each kit is designed to provide power throughout the RPM range. The extra surface area of these open-air air filters provide even more airflow at lower restriction than a K&N O/E replacement filter which is always limited to the size of the factory air box. The larger air filter also captures and holds more dirt increasing its service life before a cleaning is required (up to 100,000 miles). The filter is either directly attached to the engine carburetor or throttle body or indirectly through a tube assembly running from the filter to the engine. All adapters are made from high quality materials such as steel, aluminum, silicon or reinforced nylon to ensure long life. 57i Intakes are not legal for use in California and other US States adopting California emission standards.