K&N air filter oil: Especially for K & N cotton filters developed filter oil. This ensures that the cotton becomes light red in color, so that the oiled parts are recognizable. Instructions for oiling the filter are printed on the packaging. How often should the K & N filter be cleaned? K & N air filters are high-quality filters, both in the air passage and filter operation. The maintenance intervals depend strongly on the application. It may be that a filter at rally-cross has tob e cleaned every 150 km and a normal car after 200,000 miles. Hold this rule: a K & N filter has to be cleaned if there is a dirt layer of 2-3 mm. Inserting the filter After the filter is placed it should be checked again, if the filter is properly sealed and also make sure that there is no false air. Never use petrol, paraffin, diluent, etc. The air filter can not be cleaned with high pressure water systems. Only use K & N filter oil, as normal lubricating oil damages the cotton and hinders the air passage. Excessive oiling After cleaning the filter, you must make sure that the filter is not excessively oiled. Always apply a little amount of oil on the filter and leave the oil so set in. If there are still spots that are not colored red, only oil these spots. Too much oil impedes the passage of air. Make sure that the filter doesnt drip after installation, this may have the effect that the oil will flow into the air intake system. Follow the instructions, which are printed on the package. Also download the PDF manual (http://www.efkaimport.nl/Uploaded_files/Zelf/schoonmaak.pdf). And/or watch the instructional video: