The K&N filter has been independently tested and results show that paper and foam filters simply cannot match the K&N flow rates even when new and their performance drops off sharply when only slightly dirty. The K&N filtercharger flows like new for up to 50,000 miles without cleaning! Maximum Filtration! A K&N filter is designed to be oiled. The oil that is held in suspension by the cotton gauze material acts to stop even the smallest dirt particles from entering your engine. As dirt builds up on the outside of a K&N filter, it acts as part of the filter media further extending the filter's service life. Very High Air Flow! No other filter will flow as much air as a K&N. The extremely large surface area offers little restriction to incoming air. In fact, the special gauze-and-screen construction acts to smooth and straighten the air as it enters the intake system, increasing engine performance, hence why its called a FilterCharger! Long Filter Life! The K&N filtercharger is engineered to last the life of your engine. When extremely dirty, you simply clean with K&N filter cleaner, reverse flush with water, re-oil with K&N filter oil and reinstall. Except under extremely dusty conditions, the K&N will only need servicing every 50,000 to 100,000 of driving. Key points : High Air Flow with Excellent Filtration. IF YOU WISH TO CONFIRM THE CHOSEN FILTER IS CORRECT FOR YOUR APPLICATION PLEASE SEE THE CATALOGUE ON WWW.KNFILTERS.COM