Replaced my air cleaner just before we left for Oregon this last August. Very smoky here at home when we left, the fires were almost in our back yard. We travelled to Oregon and up to Coeur d alene ID and ran into more fires and smoke. More fires and smoke when we returned home in October. Another fire close to our home. The 'telltale' air cleaner gauge reads about normal, 11-15. Just wonder if its time to replace the air filter because of all that smoke. Guess we travelled maybe 2,000 miles; not more.